Sofia (English Wikipedia)

"Cu cine este înfrățit Bucureștiul?". Adevărul (in Romanian). 21 February 2011. Archived from the original on 18 November 2019. Retrieved 18 November 2019.

akademika.bg

"Sofia University aims to attract more foreign students" (in Bulgarian). Akademika. 14 June 2013. Archived from the original on 20 October 2013. Retrieved 19 October 2013.

ankara.bel.tr

"Sister Cities of Ankara". ankara.bel.tr. Ankara. Archived from the original on 28 April 2013. Retrieved 27 December 2019.

archaeologyinbulgaria.com

Prehistory, Ivan Dikov · in (7 December 2015). "Archaeologist Discovers 8,000-Year-Old Nephrite 'Frog-like' Swastika in Slatina Neolithic Settlement in Bulgaria's Capital Sofia – Archaeology in Bulgaria". archaeologyinbulgaria.com. Archived from the original on 22 December 2015. Retrieved 20 December 2015.

archive-it.org

wayback.archive-it.org

"Dio, Roman History, Book 51, chapter 25". Archived from the original on 28 October 2014. Retrieved 20 February 2021.

archive.org

Ghodsee, Kristen (2005). The Red Riviera: Gender, Tourism, and Postsocialism on the Black Sea. Duke University Press. p. 21. ISBN 0822387174.

archive.today

"Vitosha Mountain". vitoshamount.hit.bg. Archived from the original on 20 June 2004. Retrieved 29 April 2014.
"ערים שותפות". tel-aviv.gov.il (in Hebrew). Tel Aviv. Archived from the original on 18 November 2017. Retrieved 19 May 2021.

balkanvolleyball.org

"BVA-News". balkanvolleyball.org. Archived from the original on 20 February 2008. Retrieved 11 May 2008.

bas.bg

geography.iit.bas.bg

"Archived copy" (PDF). Archived from the original (PDF) on 6 July 2011. Retrieved 14 February 2010.{{cite web}}: CS1 maint: archived copy as title (link)

bbc.co.uk

news.bbc.co.uk

"BBC NEWS – Europe – Romania and Bulgaria join the EU". bbc.co.uk. Archived from the original on 29 May 2021. Retrieved 25 September 2016.

bluelink.net

old.bluelink.net

"General Hydrological Data". Iskar River System. Archived from the original on 7 December 2017. Retrieved 27 April 2019.

bnr.bg

"(source)". Archived from the original on 16 August 2016. Retrieved 16 July 2016.
"Sofia, Shanghai to become sister cities". bnr.bg. BNR Radio Bulgaria. 23 November 2015. Archived from the original on 27 December 2019. Retrieved 27 December 2019.

bnt.bg

"Sofia is one of the top 10 places for start-up businesses in the world, Bulgarian National TV". Bnt.bg. Archived from the original on 22 December 2015. Retrieved 11 April 2018.
"Sofia Municipal Council Adopted Measures to Tackle Air Pollution". Bulgarian National Television. 25 January 2018. Archived from the original on 27 October 2018. Retrieved 26 October 2018.
""Триъгълникът на властта" или Ларгото: Как се е променял през годините" [The Triangle of Power or The Largo: How It Changed Throughout the Years]. Bulgarian National Television. Archived from the original on 6 June 2020. Retrieved 1 November 2018.
"Българска национална телевизия – Новини (Bulgarian National Television – News)" (in Bulgarian). bnt.bg. Archived from the original on 3 September 2012. Retrieved 2 September 2012.

news.bnt.bg

"Как ще изглежда новата пленарна зала на българските депутати?" [What will the new Parliament hall look like?]. Bulgarian National Television. 2 October 2018. Archived from the original on 29 May 2021. Retrieved 1 November 2018.

books.google.com

Bulgaria, Hungary, Romania, the Czech Republic, and Slovakia. Britannica Educational Publishing. 1 June 2013. ISBN 9781615309870. Archived from the original on 21 February 2021. Retrieved 12 September 2017.
Lauwerys, Joseph (1970). Education in Cities. Evan's Brothers. ISBN 0-415-39291-8. Archived from the original on 11 July 2020. Retrieved 12 September 2017.
Rogers, Clifford (2010). The Oxford Encyclopedia of Medieval Warfare and Military Technology. Vol. 1. Oxford University Press. p. 301. ISBN 9780195334036. Archived from the original on 17 July 2020. Retrieved 27 June 2019.
Grant, Michael (211). The Emperor Constantine. Hachette. ISBN 9781780222806. Archived from the original on 18 August 2020. Retrieved 12 September 2017.
World and Its Peoples. Marshall Cavendish. 2010. ISBN 9780761479024. Archived from the original on 18 August 2020. Retrieved 12 September 2017.
Irina Florov, Nicholas Florov (2001). Three-thousand-year-old Hat. Michigan University: Golden Vine Publishers. p. 303. ISBN 0968848702. Archived from the original on 28 September 2017. Retrieved 12 September 2017.
Erwin Anton Gutkind (1964). International history of city development (8 ed.). Michigan University: Free Press of Glencoe. Archived from the original on 20 August 2020. Retrieved 12 September 2017.
Encyclopedia Americana (25 ed.). Pennsylvania State University: Grolier Incorporated. 1999. p. 878. ISBN 0717201317. Archived from the original on 21 February 2017. Retrieved 12 September 2017.
Ishirkov, Anastas (1910). "Атанас Иширков, България. Географически бележки, Придворна печатница, 1910 година, стр. 78". Archived from the original on 7 August 2020. Retrieved 3 September 2019.
John G. Kelcey; Norbert Müller (7 June 2011). Plants and Habitats of European Cities. Czech Republic; Germany – University of Applied Sciences Erfurt: Springer. ISBN 978-0-387-89684-7. Archived from the original on 19 August 2020. Retrieved 12 September 2017.
Trudy, Ring; Noelle, Watson; Paul, Schellinger (5 November 2013). Southern Europe: International Dictionary of Historic Places. Routledge. ISBN 9781134259588. Archived from the original on 19 August 2020. Retrieved 20 December 2015.
"Trakii︠a︡ – Том 12 – Страница 41- "Da diese mit ihrem blinden König Siras verbündete der Römer waren ergab dies den Vorwand für den Kriegszug von Crassus. Über die Segetike (wohl irrtümlich für Serdike, Land der Serden, wie es aus Dio Cass. LI, 25, 4 erhellt)"". 1998. Archived from the original on 12 October 2018. Retrieved 12 October 2018.
"Acta Antiqua Academiae Scientiarum Hungaricae. Akademai Klado, 1966. "Als sie die Dentheleten angriffen, kam Crassus diesen zur. Hilfe, eroberte das Land der Serden (bei Dio Segetika) und kam plündernd ins."". 1966. Archived from the original on 12 October 2018. Retrieved 12 October 2018.
Jenő Fitz. Limes. Akadémiai Kiadó, 1977 "As Macedonia itself was in danger, Crassus readily advanced as far as Segetika (-Serdica)" Archived 12 October 2018 at the Wayback Machine, ISBN 9789630513012
Ivanov, Rumen (2006). Roman cities in Bulgaria. Bulgarian Bestseller--National Museum of Bulgarian Books and Polygraphy. ISBN 9789544630171. Archived from the original on 20 August 2020. Retrieved 12 September 2017.
Wilkes, John (2005). "Provinces and Frontiers". In Bowman, Alan K.; Garnsey, Peter; Cameron, Averil (eds.). The Cambridge ancient history: The crisis of empire, A.D. 193–337. Vol. 12. Cambridge University Press. p. 253. ISBN 978-0-521-30199-2. Archived from the original on 10 November 2015. Retrieved 29 October 2015.
Encyclopaedia Londinensis, or, Universal dictionary of arts, sciences, and literature. University of Minnesota. 1827. Archived from the original on 19 August 2020. Retrieved 12 September 2017.
Nikolova, Kapka Sofia Archived 20 August 2020 at the Wayback Machine University of Indiana. "Emperor Constantine the Great even considered the possibility for Serdika to become the capital of the Eastern Roman Empire"
Green, Bernard (2010). Christianity in Ancient Rome: The First Three Centuries. A&C Black. p. 237. ISBN 978-0-567-03250-8. Archived from the original on 19 August 2020. Retrieved 12 September 2017.
Slaviani. 1967. Archived from the original on 18 August 2020. Retrieved 27 June 2019.
Godisnjak. Drustvo Istoricara Bosne i Hercegovine, Sarajevo. 1950. p. 174. Archived from the original on 18 August 2020. Retrieved 27 June 2019. Санџак Софија Овај је санџак основан око г. 1393.
David Coulby; Robert Cowen; Crispin Jones (17 January 2013). World Yearbook of Education 2000: Education in Times of Transition. Routledge. p. 10. ISBN 978-1-136-16603-7. Archived from the original on 18 April 2016. Retrieved 29 October 2015. crime rates have exploded in Sofia as well as in Moscow and St Petersburg.
Gergana Noutcheva (26 July 2012). European Foreign Policy and the Challenges of Balkan Accession: Conditionality, legitimacy and compliance. Routledge. p. 192. ISBN 978-1-136-30619-8. Archived from the original on 18 April 2016. Retrieved 29 October 2015. The strongest EU demand – structural changes of the judicial system – had to do with the crime rate in Bulgaria and the apparent impotence of the authorities in Sofia to convict any of the murderes in the high-profile mafia killings that shook the country in 2003–2005.
Ecker, Gerhard (1984). Bulgarien. Kunstdenkmäler aus vier Jahrtausenden von den Thrakern bis zur Gegenwart (in German). Köln: DuMont Buchverlag. ISBN 9783406398667. Archived from the original on 20 August 2020. Retrieved 12 September 2017.

britannica.com

"Sofia". Encyclopædia Britannica. Archived from the original on 17 September 2018. Retrieved 12 February 2016.

brookings.edu

"Global Metro Monitor An Uncertain recovery" (PDF). brookings.edu. Archived (PDF) from the original on 2 April 2015. Retrieved 22 January 2015.

bta.bg

"Sofia, Budapest to Cooperate in Culture, Tourism, Economy". Archived from the original on 11 May 2018. Retrieved 11 May 2018.

btvnovinite.bg

"bTV". 6 November 2023.
"Народното събрание – музей?" [The National Assembly – a Museum?]. BTV Novinite. 7 October 2018. Archived from the original on 8 October 2018. Retrieved 1 November 2018.

bulgariawinetours.com

BulWTours (20 July 2015). "Odrysian Kingdom - the first country on the Balkans". Bulgaria Wine Tours. Archived from the original on 9 February 2022. Retrieved 8 September 2021.

businessinsider.com

"The Most Dangerous Cities in Europe". Business Insider Inc. Archived from the original on 2 July 2015. Retrieved 23 October 2015.

businesspark-sofia.com

"Hewlett-Packard Bulgaria". Business Park Sofia. Archived from the original on 17 July 2020. Retrieved 14 July 2020.

capital.bg

Zapryanov, Yoan (22 June 2018). "Малката изчислителна армия на България" [Bulgaria's small computing army] (in Bulgarian). Kapital Daily. Archived from the original on 17 November 2019. Retrieved 15 July 2018.

catholic.com

oce.catholic.com

This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed. (1913). "Sardica". Catholic Encyclopedia. New York: Robert Appleton Company.

cik.bg

results.cik.bg

cik.bg

"РЕШЕНИЕ № 4149-НС София, 27.01.2017" [Resolution No. 4149-NS Sofia]. Central Electoral Commission. 27 January 2017. Archived from the original on 4 April 2019. Retrieved 1 November 2018.

climatebase.ru

"Browser Check Page".

cm-lisboa.pt

"Acordos de geminação, de cooperação e de amizade". cm-lisboa.pt (in Portuguese). Lisboa. Archived from the original on 31 October 2013. Retrieved 27 December 2019.

dak-transport.com

"Transport Company Bulgaria— official website" (in Bulgarian). dak-transport.com. Archived from the original on 7 September 2009. Retrieved 21 August 2009.

dnevnik.bg

"Fines for bad repair work – 'Dnevnik' newspaper". dnevnik.bg. Archived from the original on 13 January 2009. Retrieved 24 May 2008.

economist.com

"Bulgarian Crime – Where killing is a habit". The Economist. 27 October 2005. Archived from the original on 29 June 2015. Retrieved 21 October 2015.

espon-usespon.eu

"Metropolitan areas in Europe" (PDF). Der Markt für Wohn- und Wirtschaftsimmobilien in Deutschland Ergebnisse des BBSR-Expertenpanel Immobilienmarkt Nr: 95. ISSN 1868-0097. Archived from the original (PDF) on 15 July 2018. Retrieved 15 July 2018.

europa.eu

appsso.eurostat.ec.europa.eu

"Archived copy". Archived from the original on 24 November 2020. Retrieved 25 August 2020.{{cite web}}: CS1 maint: archived copy as title (link)
"Eurostat – Data Explorer". appsso.eurostat.ec.europa.eu. Archived from the original on 3 December 2018. Retrieved 21 December 2016.
"Eurostat-Sofia urban area population". Archived from the original on 3 September 2015. Retrieved 24 June 2017.

ec.europa.eu

"Population on 1 January by age groups and sex - functional urban areas".
"Air Quality Standards". European Commission. Archived from the original on 22 October 2018. Retrieved 26 October 2018.
"Regional gross domestic product (PPS per inhabitant at current market prices), by NUTS 3 regions". Eurostat. Archived from the original on 11 April 2016. Retrieved 12 March 2017.

forbes.com

"10 Top Cities Around The World To Launch Your Startup". Forbes. 29 November 2015. Archived from the original on 14 March 2016. Retrieved 13 March 2016.

gdin.bg

The prison in Sofia Archived 4 March 2016 at the Wayback Machine. Gdin

ghostarchive.org

Environment: Sofia, most polluted capital of Europe (News report). Agence France-Presse. 20 December 2015. Archived from the original on 30 October 2021. Retrieved 26 October 2018.

globaldatalab.org

hdi.globaldatalab.org

"Sub-national HDI - Area Database - Global Data Lab". hdi.globaldatalab.org. Archived from the original on 23 September 2018. Retrieved 13 September 2018.

guide-bulgaria.com

"District Sofia-city". Guide Bulgaria. Archived from the original on 29 February 2012. Retrieved 19 February 2012.

historymuseum.org

"Колекции – НИМ". Historymuseum.org. Archived from the original on 17 February 2015. Retrieved 11 April 2018.

hit.bg

vitoshamount.hit.bg

"Vitosha Mountain". vitoshamount.hit.bg. Archived from the original on 20 June 2004. Retrieved 29 April 2014.

hostel.com

internethostelsofia.hostel.com

Internet Hostel Sofia, Tourism in Sofia Archived 28 December 2011 at the Wayback Machine. Internethostelsofia.hostel.com, Retrieved Jan 2012

i-c-d.de

"Triangle of Religious Tolerance (1903) – iCulturalDiplomacy". www.i-c-d.de. Archived from the original on 27 January 2020. Retrieved 27 December 2019.

imdb.com

"London Has Fallen: Company Credits". IMDb.com. Archived from the original on 27 January 2017. Retrieved 28 October 2018.

investsofia.com

"IT Sector in Sofia". Invest Sofia. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Coca-Cola Opens Its 2nd Largest Globally IT Center in Sofia". Invest Sofia. 9 June 2018. Archived from the original on 16 July 2020. Retrieved 14 July 2020.
"VMware to invest €23M and Grow the Site in Sofia to over 1500 People". Invest Sofia. 7 May 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Bosch Group Officially Opened its New Office in Sofia". Invest Sofia. 25 June 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Financial Times Expands Its Team in Sofia". Invest Sofia. 2 July 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"The Software Company Experian Opened its New Office Building in Sofia". Invest Sofia. 8 June 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"IT Manufacturing in Sofia". Invest Sofia. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"American Control System Solutions Manufacturer Woodward Opens Production in Sofia". Invest Sofia. 27 February 2017. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Festo to Invest 25.6 mln. Euro in a New Production Unit in Sofia/". Invest Sofia. 7 June 2018. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Melexis to Invest €75M to Expand Its Operations in Bulgaria". Invest Sofia. 25 June 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.

journey.bg

"National parks in the world" (in Bulgarian). journey.bg. Archived from the original on 23 May 2008. Retrieved 24 May 2008.
"Journey.bg — History of the Sofia velodrome". journey.bg. Archived from the original on 15 May 2005. Retrieved 11 May 2008.

kmeta.bg

"История". www.kmeta.bg. 10 May 2017. Archived from the original on 31 October 2018. Retrieved 31 October 2018.

kultura.bg

"Емил Коцев 24.04.2016 9:331205 ИЗГУБЕНАТА СТОЛИЦА". Archived from the original on 4 February 2017. Retrieved 12 October 2018.

kunki.org

"Skate rinks in Sofia". kunki.org. Archived from the original on 17 April 2008. Retrieved 11 May 2008.

kupdf.net

Kemal Karpat (1985), Ottoman Population, 1830-1914, Demographic and Social Characteristics Archived 10 October 2019 at the Wayback Machine, The University of Wisconsin Press, p. 36

kyivcity.gov.ua

old.kyivcity.gov.ua

"Перелік міст, з якими Києвом підписані документи про поріднення, дружбу, співробітництво, партнерство" (PDF). kyivcity.gov.ua (in Ukrainian). Kyiv. 15 February 2018. Archived (PDF) from the original on 28 January 2020. Retrieved 19 May 2021.

lboro.ac.uk

"The World According to GaWC 2020". GaWC - Research Network. Globalization and World Cities. Archived from the original on 24 August 2020. Retrieved 31 August 2020.

lib.ru

militera.lib.ru

"ВОЕННАЯ ЛИТЕРАТУРА --[ Военная история ]-- Генов Ц. Русско-турецкая война 1877–1878 гг. и подвиг освободителей". lib.ru. Archived from the original on 5 March 2016. Retrieved 8 August 2015.

live.com

view.officeapps.live.com

longfinance.net

"The Global Financial Centres Index 27" (PDF). Long Finance. March 2020. Archived (PDF) from the original on 28 March 2020. Retrieved 3 September 2020.

madrid.es

"Agreements with cities". madrid.es. Madrid. Archived from the original on 10 June 2020. Retrieved 27 December 2019.

maleevaclub.com

"Тенис Клуб Малееви". maleevaclub.com. Archived from the original on 14 March 2008. Retrieved 11 May 2008.

mashke.org

pop-stat.mashke.org

"Cities of Bulgaria". 3 April 2024.

mediapool.bg

""Дружба", "Надежда" и "Павлово" са с най-мръсен въздух в София – Mediapool.bg". mediapool.bg. 16 March 2012. Archived from the original on 4 March 2016. Retrieved 13 August 2015.
"Ромите са изолирани от бума в заетостта на Балканите". Mediapool.bg. 11 December 2007. Archived from the original on 6 July 2011. Retrieved 11 April 2018.

metropolitan.bg

"ОП Транспорт и разширение". Metropolitan.bg. Archived from the original on 14 August 2011. Retrieved 2 May 2018.
"Metropolitan Sofia Web Place". metropolitan.bg. Archived from the original on 1 October 2008. Retrieved 24 May 2008.
"General Scheme". Metropolitan.bg. Archived from the original on 14 May 2013. Retrieved 12 March 2013.

milarodino.com

"София" (in Bulgarian). Мила Родино. Archived from the original on 19 December 2007. Retrieved 14 September 2008.

mon.bg

rvu.mon.bg

"Register of Higher Schools in Bulgaria". Ministry of Education and Science. Archived from the original on 27 October 2018. Retrieved 27 October 2018.

msb.bg

"MSB – Projects". www.msb.bg. Archived from the original on 28 October 2018. Retrieved 27 October 2018.

nationalgallery.bg

"Museum of Socialist Art – National Gallery". Archived from the original on 21 December 2019. Retrieved 27 December 2019.

nationallibrary.bg

"Funds and collections". SS. Cyril and Methodius National Library. Archived from the original on 28 October 2018. Retrieved 28 October 2018.

nftvb.com

"National Federation of the Taxi Drivers in Bulgaria. Regional Member Sofia". nftvb.com. Archived from the original on 2 June 2008. Retrieved 24 May 2008.

noaa.gov

nodc.noaa.gov

"Index of /Archive/Arc0216/0253808/2.2/Data/0-data/Region-6-WMO-Normals-9120/Bulgaria/CSV".

ncei.noaa.gov

"Station Name: Sofia". United States National Oceanic and Atmospheric Administration. Retrieved 13 August 2024.

noviiskar.wordpress.com

Софийска голяма община – климат Archived 7 August 2020 at the Wayback Machine.

novinar.bg

"E-novinar.com – Новините на едно място" [Mohailova, Tihomria. In 1900 the first electric lamp lit the streets of Sofia. Novinar]. novinar.bg (in Bulgarian). 12 March 2014. Archived from the original on 18 June 2016. Retrieved 22 December 2016.

novini247.com

"През 2000 година на 5 юли е бил един от". 4 July 2023.

novinite.com

Crime Rates in Bulgaria's Sofia on the Rise Archived 22 May 2015 at the Wayback Machine Novinite
"UPDATE: Stallone Returning to NU BOYANA Film Studios in Bulgaria for 'Rambo 5'". Novinite. 30 August 2018. Archived from the original on 31 August 2018. Retrieved 28 October 2018.
"Shared Electric Vehicles Spark in Sofia Increase by 170". Novinite. 13 March 2019. Archived from the original on 29 March 2019. Retrieved 30 March 2019.
"Bulgaria's Nuclear Institute: New Cyclotron To Become Operational in 2 Years". Novinite. 27 October 2016. Archived from the original on 27 October 2018. Retrieved 27 October 2018.

nsi.bg

"CITIES AND THEIR URBANISED AREAS IN THE REPUBLIC OF BULGARIA" (PDF). National Statistical Institute: 91. Archived (PDF) from the original on 15 July 2018. Retrieved 15 July 2018.
"Nsi • National Register of Populated Places •". Archived from the original on 11 July 2020. Retrieved 8 July 2020.
"Население по градове и пол | Национален статистически институт". www.nsi.bg (in Bulgarian). Archived from the original on 12 April 2021. Retrieved 29 May 2021.
"NATIONAL STATISTICAL INSTITUTE – Information for the area of city of Sofia". Nsi.bg. Archived from the original on 7 February 2018. Retrieved 11 April 2018.
"Population | National statistical institute". www.nsi.bg. Archived from the original on 26 October 2018. Retrieved 31 October 2018.
"Population". nsi.bg. National Statistical Institute of Bulgaria, 2011. Archived from the original on 3 March 2016. Retrieved 12 February 2016.
"Population and Demographic Processes in 2014 (Final data) – National statistical institute". Nsi.bg. Archived from the original on 15 November 2016. Retrieved 11 April 2018.
"GDP by Economic Sector and Region". National Statistical Institute. Archived from the original on 16 July 2020. Retrieved 14 July 2020.
"Average monthly wages and salaries of the employees under labour contract by statistical regions and districts". National Statistical Institute. Archived from the original on 7 June 2020. Retrieved 14 July 2020.
"Sofia (capital)". National Statistical Institute regional statistics. 11 February 2013. Archived from the original on 14 November 2013. Retrieved 17 October 2013.

statlib.nsi.bg

2011 census, Sofia-capital (PDF) (23 ed.). Sofia: National Statistical Institute of Bulgaria. 2012. p. 37 40 43 68 71 74 99 117 132 190 193 196. Archived from the original (PDF) on 15 February 2016.

numbeo.com

"Crime in Sofia. Safety in Sofia". Archived from the original on 19 September 2015. Retrieved 21 October 2015.

nytimes.com

Hakim, Danny (15 October 2013). "Bulgaria's Air Is Dirtiest in Europe, Study Finds, Followed by Poland". The New York Times. Archived from the original on 23 July 2014. Retrieved 15 October 2013.

offnews.bg

"Кои са най-желаните гимназии в София и кои паралелки останаха празни" [Which high schools in Sofia are the most preferred]. Offnews. 3 July 2018. Archived from the original on 27 October 2018. Retrieved 27 October 2018.

omda.bg

old.omda.bg

"Sofia – Trip around Sofia". Balkan tourist, 1968. Archived from the original on 5 March 2016. Retrieved 8 August 2015.

opoznai.bg

"Градина "Алжир" – София". opoznai.bg (in Bulgarian). 19 June 2015. Archived from the original on 19 May 2021. Retrieved 19 May 2021.

osac.gov

"Bulgaria 2015 Crime and Safety Report". 29 December 2016. Archived from the original on 29 December 2016.

paris.fr

"Friendship and cooperation agreements". Paris.fr. Archived from the original on 15 October 2013. Retrieved 12 October 2013.

pressarabia.qa

"HE Prime Minister Presides Over Cabinet Regular Meeting". pressarabia.qa. Press Arabia. 28 November 2012. Archived from the original on 18 October 2020. Retrieved 19 May 2021.

regionalprofiles.bg

"Sofia (capital)".

researchgate.net

L. Ivanov. 1991 Sofia street naming proposal. Archived 25 October 2017 at the Wayback Machine Sofia City Place-names Commission, 22 January 1991.

seenews.com

wire.seenews.com

"Sofia ranks 30th in GDP/capita, employment growth 2013–2014 global report". seenews.com. Archived from the original on 21 June 2015. Retrieved 22 January 2015.

sipagroup.com

news.sipagroup.com

"Lufthansa Technik Sofia invests 30 mln euro to expand its facilities". SIPA Group. Archived from the original on 16 July 2020. Retrieved 14 July 2020.

sistercitiespgh.org

"Our Sister Cities". sistercitiespgh.org. Sister Cities Association of Pittsburgh. Archived from the original on 19 May 2021. Retrieved 19 May 2021.

sofia-airport.bg

"Passengers 2018-2019" (PDF). Sofia Airport. Archived (PDF) from the original on 9 June 2020. Retrieved 14 July 2020.

sofia.bg

"Sofia through centuries". Sofia Municipality. Archived from the original on 19 August 2009. Retrieved 16 October 2009.
"District Mayors". Sofia Municipality. Archived from the original on 20 December 2009. Retrieved 26 December 2009.
"Sofia municipality — Tennis courts". sofia.bg. Retrieved 11 May 2008.^{[permanent dead link‍]}
Sofia infrastructure from the official website of the Municipality Archived 28 May 2008 at the Wayback Machine (in Bulgarian)

council.sofia.bg

"Sofia Council - Общински съветници 2023-2027". council.sofia.bg. Retrieved 2 July 2024.

sofiaculture.bg

"София – 130 години столица на България". sofiaculture.bg. Archived from the original on 5 September 2017.

sofiaecho.com

"Kapital Quarterly". Sofiaecho.com. Archived from the original on 10 June 2016. Retrieved 11 April 2018.

sofiaglobe.com

"Air pollution in Sofia, other Bulgarian cities hugely exceeded norms several times this winter". The Sofia Globe. 4 April 2018. Archived from the original on 26 October 2018. Retrieved 26 October 2018.
"Bulgaria: Bad air quality in Sofia on January 6 2018". The Sofia Globe. 6 January 2018. Archived from the original on 26 October 2018. Retrieved 26 October 2018.

sofiatraffic.bg

"History of the bus network in Sofia". Sofiatraffic.bg. Archived from the original on 27 August 2013. Retrieved 30 August 2012.
"History of the tramway network in Sofia". Sofiatraffic.bg. Archived from the original on 30 June 2016. Retrieved 30 August 2012.
"History of the trolleybus network in Sofia". Sofiatraffic.bg. 14 February 1941. Archived from the original on 27 August 2013. Retrieved 30 August 2012.)

sredec-sofia.org

"History". Capital Municipality. Archived from the original on 26 December 2015. Retrieved 20 October 2015.

standartnews.com

"Brussels: Sofia has no projects targeting air pollutionКопирано от fidget.bg". Standard. 12 September 2018. Archived from the original on 27 October 2018. Retrieved 26 October 2018.

stringmeteo.com

Николов, Иван. "Архив-Бг3 » 01-1991 София". stringmeteo.com. Archived from the original on 29 May 2021. Retrieved 1 January 2021.
"Статистически Данни" (PDF). stringmeteo.com. Retrieved 13 August 2024.
Николов, Иван. "Времето София » 25.12.2001". stringmeteo.com. Archived from the original on 3 April 2015. Retrieved 28 January 2015.
"Вековен архив - София » 01.1887 - 12.2007". www.stringmeteo.com. Archived from the original on 17 May 2021. Retrieved 17 May 2021.
"Времето-България » Мес. обобщ. температури".
"Архив-Бг » Год. обобщ. температури".
"Век. месечен архив Бг". Archived from the original on 7 August 2020. Retrieved 18 January 2020.
"Архив-Бг » Год. обобщ. валежи". Archived from the original on 7 August 2020. Retrieved 18 January 2020.
"Век. месечен архив Бг". Stringmeteo.com.
"Век. месечен архив Бг". Stringmeteo.com.
"Времето София » 05.11.2021".

sumc.bg

"Public transport Sofia — official website" (in Bulgarian). sumc.bg. Archived from the original on 29 May 2021. Retrieved 24 May 2008.

tel-aviv.gov.il

"ערים שותפות". tel-aviv.gov.il (in Hebrew). Tel Aviv. Archived from the original on 18 November 2017. Retrieved 19 May 2021.

theculturetrip.com

"10 Things We Can all Learn from Bulgaria's Square of Religious Tolerance". 15 February 2017. Archived from the original on 29 September 2020. Retrieved 4 September 2020.

theguardian.com

Chalabi, Mona (30 November 2012). "Where are world's deadliest major cities?". theguardian.com. Archived from the original on 23 January 2017. Retrieved 25 September 2016.

thelatinlibrary.com

"Eutropius: Book IX". thelatinlibrary.com. Archived from the original on 10 September 2017. Retrieved 16 February 2012.

tialoto.bg

tonus.tialoto.bg

"Swimming pools in Sofia (including Spa centers)". tonus.tialoto.bg. Archived from the original on 10 May 2008. Retrieved 11 May 2008.

trud.bg

"Н. пр. д-р Хасан Бармауи, почетен консул на кралство Йордания в България, пред "Труд": Йордания е врата за България към Близкия Изток". trud.bg (in Bulgarian). Trud. 25 February 2020. Archived from the original on 19 May 2021. Retrieved 19 May 2021.

ubisoft.com

"Ubisoft Sofia". www.ubisoft.com. Archived from the original on 15 August 2022. Retrieved 13 August 2022.

uchicago.edu

penelope.uchicago.edu

"Dio, Roman History, Book 51, chapter 25". Archived from the original on 28 October 2014. Retrieved 20 February 2021.

uni-plovdiv.net

web.uni-plovdiv.net

https://web.uni-plovdiv.net/vedrin/sg/sg-bg-1947-1948.pdf ^{[bare URL PDF]}

uni-sofia.bg

"Official website of the Sofia university — History". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"University Faculties". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"Independent structures of SU". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"Faculty of Physics structure". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"University Centres". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.

usatoday.com

Clark, Jayne. "Is Europe's most affordable capital worth the trip?". USA Today. Archived from the original on 6 April 2016. Retrieved 12 February 2016.

visteon.bg

"Products". Visteon Electronics Bulgaria. Archived from the original on 14 July 2020. Retrieved 14 July 2020.

weather-atlas.com

"Sofia, Bulgaria - Detailed climate information and monthly weather forecast". Archived from the original on 9 March 2021. Retrieved 3 September 2019.

web.archive.org

"Sofia through centuries". Sofia Municipality. Archived from the original on 19 August 2009. Retrieved 16 October 2009.
Prehistory, Ivan Dikov · in (7 December 2015). "Archaeologist Discovers 8,000-Year-Old Nephrite 'Frog-like' Swastika in Slatina Neolithic Settlement in Bulgaria's Capital Sofia – Archaeology in Bulgaria". archaeologyinbulgaria.com. Archived from the original on 22 December 2015. Retrieved 20 December 2015.
"CITIES AND THEIR URBANISED AREAS IN THE REPUBLIC OF BULGARIA" (PDF). National Statistical Institute: 91. Archived (PDF) from the original on 15 July 2018. Retrieved 15 July 2018.
"Archived copy". Archived from the original on 24 November 2020. Retrieved 25 August 2020.{{cite web}}: CS1 maint: archived copy as title (link)
"Nsi • National Register of Populated Places •". Archived from the original on 11 July 2020. Retrieved 8 July 2020.
"Население по градове и пол | Национален статистически институт". www.nsi.bg (in Bulgarian). Archived from the original on 12 April 2021. Retrieved 29 May 2021.
"Eurostat – Data Explorer". appsso.eurostat.ec.europa.eu. Archived from the original on 3 December 2018. Retrieved 21 December 2016.
"Sub-national HDI - Area Database - Global Data Lab". hdi.globaldatalab.org. Archived from the original on 23 September 2018. Retrieved 13 September 2018.
"Sofia". Encyclopædia Britannica. Archived from the original on 17 September 2018. Retrieved 12 February 2016.
Bulgaria, Hungary, Romania, the Czech Republic, and Slovakia. Britannica Educational Publishing. 1 June 2013. ISBN 9781615309870. Archived from the original on 21 February 2021. Retrieved 12 September 2017.
Lauwerys, Joseph (1970). Education in Cities. Evan's Brothers. ISBN 0-415-39291-8. Archived from the original on 11 July 2020. Retrieved 12 September 2017.
Rogers, Clifford (2010). The Oxford Encyclopedia of Medieval Warfare and Military Technology. Vol. 1. Oxford University Press. p. 301. ISBN 9780195334036. Archived from the original on 17 July 2020. Retrieved 27 June 2019.
Internet Hostel Sofia, Tourism in Sofia Archived 28 December 2011 at the Wayback Machine. Internethostelsofia.hostel.com, Retrieved Jan 2012
"Triangle of Religious Tolerance (1903) – iCulturalDiplomacy". www.i-c-d.de. Archived from the original on 27 January 2020. Retrieved 27 December 2019.
"10 Things We Can all Learn from Bulgaria's Square of Religious Tolerance". 15 February 2017. Archived from the original on 29 September 2020. Retrieved 4 September 2020.
"Sofia is one of the top 10 places for start-up businesses in the world, Bulgarian National TV". Bnt.bg. Archived from the original on 22 December 2015. Retrieved 11 April 2018.
Clark, Jayne. "Is Europe's most affordable capital worth the trip?". USA Today. Archived from the original on 6 April 2016. Retrieved 12 February 2016.
"Museum of Socialist Art – National Gallery". Archived from the original on 21 December 2019. Retrieved 27 December 2019.
"История". www.kmeta.bg. 10 May 2017. Archived from the original on 31 October 2018. Retrieved 31 October 2018.
"NATIONAL STATISTICAL INSTITUTE – Information for the area of city of Sofia". Nsi.bg. Archived from the original on 7 February 2018. Retrieved 11 April 2018.
"Eurostat-Sofia urban area population". Archived from the original on 3 September 2015. Retrieved 24 June 2017.
"Metropolitan areas in Europe" (PDF). Der Markt für Wohn- und Wirtschaftsimmobilien in Deutschland Ergebnisse des BBSR-Expertenpanel Immobilienmarkt Nr: 95. ISSN 1868-0097. Archived from the original (PDF) on 15 July 2018. Retrieved 15 July 2018.
Grant, Michael (211). The Emperor Constantine. Hachette. ISBN 9781780222806. Archived from the original on 18 August 2020. Retrieved 12 September 2017.
World and Its Peoples. Marshall Cavendish. 2010. ISBN 9780761479024. Archived from the original on 18 August 2020. Retrieved 12 September 2017.
Irina Florov, Nicholas Florov (2001). Three-thousand-year-old Hat. Michigan University: Golden Vine Publishers. p. 303. ISBN 0968848702. Archived from the original on 28 September 2017. Retrieved 12 September 2017.
Erwin Anton Gutkind (1964). International history of city development (8 ed.). Michigan University: Free Press of Glencoe. Archived from the original on 20 August 2020. Retrieved 12 September 2017.
"София" (in Bulgarian). Мила Родино. Archived from the original on 19 December 2007. Retrieved 14 September 2008.
Encyclopedia Americana (25 ed.). Pennsylvania State University: Grolier Incorporated. 1999. p. 878. ISBN 0717201317. Archived from the original on 21 February 2017. Retrieved 12 September 2017.
"History". Capital Municipality. Archived from the original on 26 December 2015. Retrieved 20 October 2015.
"District Sofia-city". Guide Bulgaria. Archived from the original on 29 February 2012. Retrieved 19 February 2012.
"General Hydrological Data". Iskar River System. Archived from the original on 7 December 2017. Retrieved 27 April 2019.
Софийска голяма община – климат Archived 7 August 2020 at the Wayback Machine.
Ishirkov, Anastas (1910). "Атанас Иширков, България. Географически бележки, Придворна печатница, 1910 година, стр. 78". Archived from the original on 7 August 2020. Retrieved 3 September 2019.
Николов, Иван. "Архив-Бг3 » 01-1991 София". stringmeteo.com. Archived from the original on 29 May 2021. Retrieved 1 January 2021.
Николов, Иван. "Времето София » 25.12.2001". stringmeteo.com. Archived from the original on 3 April 2015. Retrieved 28 January 2015.
"Вековен архив - София » 01.1887 - 12.2007". www.stringmeteo.com. Archived from the original on 17 May 2021. Retrieved 17 May 2021.
"Век. месечен архив Бг". Archived from the original on 7 August 2020. Retrieved 18 January 2020.
"Архив-Бг » Год. обобщ. валежи". Archived from the original on 7 August 2020. Retrieved 18 January 2020.
"Sofia, Bulgaria - Detailed climate information and monthly weather forecast". Archived from the original on 9 March 2021. Retrieved 3 September 2019.
""Дружба", "Надежда" и "Павлово" са с най-мръсен въздух в София – Mediapool.bg". mediapool.bg. 16 March 2012. Archived from the original on 4 March 2016. Retrieved 13 August 2015.
"Air pollution in Sofia, other Bulgarian cities hugely exceeded norms several times this winter". The Sofia Globe. 4 April 2018. Archived from the original on 26 October 2018. Retrieved 26 October 2018.
Hakim, Danny (15 October 2013). "Bulgaria's Air Is Dirtiest in Europe, Study Finds, Followed by Poland". The New York Times. Archived from the original on 23 July 2014. Retrieved 15 October 2013.
"Bulgaria: Bad air quality in Sofia on January 6 2018". The Sofia Globe. 6 January 2018. Archived from the original on 26 October 2018. Retrieved 26 October 2018.
"Air Quality Standards". European Commission. Archived from the original on 22 October 2018. Retrieved 26 October 2018.
"Sofia Municipal Council Adopted Measures to Tackle Air Pollution". Bulgarian National Television. 25 January 2018. Archived from the original on 27 October 2018. Retrieved 26 October 2018.
"Brussels: Sofia has no projects targeting air pollutionКопирано от fidget.bg". Standard. 12 September 2018. Archived from the original on 27 October 2018. Retrieved 26 October 2018.
John G. Kelcey; Norbert Müller (7 June 2011). Plants and Habitats of European Cities. Czech Republic; Germany – University of Applied Sciences Erfurt: Springer. ISBN 978-0-387-89684-7. Archived from the original on 19 August 2020. Retrieved 12 September 2017.
"София – 130 години столица на България". sofiaculture.bg. Archived from the original on 5 September 2017.
BulWTours (20 July 2015). "Odrysian Kingdom - the first country on the Balkans". Bulgaria Wine Tours. Archived from the original on 9 February 2022. Retrieved 8 September 2021.
Trudy, Ring; Noelle, Watson; Paul, Schellinger (5 November 2013). Southern Europe: International Dictionary of Historic Places. Routledge. ISBN 9781134259588. Archived from the original on 19 August 2020. Retrieved 20 December 2015.
"Емил Коцев 24.04.2016 9:331205 ИЗГУБЕНАТА СТОЛИЦА". Archived from the original on 4 February 2017. Retrieved 12 October 2018.
"Trakii︠a︡ – Том 12 – Страница 41- "Da diese mit ihrem blinden König Siras verbündete der Römer waren ergab dies den Vorwand für den Kriegszug von Crassus. Über die Segetike (wohl irrtümlich für Serdike, Land der Serden, wie es aus Dio Cass. LI, 25, 4 erhellt)"". 1998. Archived from the original on 12 October 2018. Retrieved 12 October 2018.
"Acta Antiqua Academiae Scientiarum Hungaricae. Akademai Klado, 1966. "Als sie die Dentheleten angriffen, kam Crassus diesen zur. Hilfe, eroberte das Land der Serden (bei Dio Segetika) und kam plündernd ins."". 1966. Archived from the original on 12 October 2018. Retrieved 12 October 2018.
Jenő Fitz. Limes. Akadémiai Kiadó, 1977 "As Macedonia itself was in danger, Crassus readily advanced as far as Segetika (-Serdica)" Archived 12 October 2018 at the Wayback Machine, ISBN 9789630513012
Ivanov, Rumen (2006). Roman cities in Bulgaria. Bulgarian Bestseller--National Museum of Bulgarian Books and Polygraphy. ISBN 9789544630171. Archived from the original on 20 August 2020. Retrieved 12 September 2017.
Wilkes, John (2005). "Provinces and Frontiers". In Bowman, Alan K.; Garnsey, Peter; Cameron, Averil (eds.). The Cambridge ancient history: The crisis of empire, A.D. 193–337. Vol. 12. Cambridge University Press. p. 253. ISBN 978-0-521-30199-2. Archived from the original on 10 November 2015. Retrieved 29 October 2015.
Encyclopaedia Londinensis, or, Universal dictionary of arts, sciences, and literature. University of Minnesota. 1827. Archived from the original on 19 August 2020. Retrieved 12 September 2017.
"Eutropius: Book IX". thelatinlibrary.com. Archived from the original on 10 September 2017. Retrieved 16 February 2012.
Nikolova, Kapka Sofia Archived 20 August 2020 at the Wayback Machine University of Indiana. "Emperor Constantine the Great even considered the possibility for Serdika to become the capital of the Eastern Roman Empire"
Green, Bernard (2010). Christianity in Ancient Rome: The First Three Centuries. A&C Black. p. 237. ISBN 978-0-567-03250-8. Archived from the original on 19 August 2020. Retrieved 12 September 2017.
Slaviani. 1967. Archived from the original on 18 August 2020. Retrieved 27 June 2019.
Godisnjak. Drustvo Istoricara Bosne i Hercegovine, Sarajevo. 1950. p. 174. Archived from the original on 18 August 2020. Retrieved 27 June 2019. Санџак Софија Овај је санџак основан око г. 1393.
"Sofia – Trip around Sofia". Balkan tourist, 1968. Archived from the original on 5 March 2016. Retrieved 8 August 2015.
Kemal Karpat (1985), Ottoman Population, 1830-1914, Demographic and Social Characteristics Archived 10 October 2019 at the Wayback Machine, The University of Wisconsin Press, p. 36
"ВОЕННАЯ ЛИТЕРАТУРА --[ Военная история ]-- Генов Ц. Русско-турецкая война 1877–1878 гг. и подвиг освободителей". lib.ru. Archived from the original on 5 March 2016. Retrieved 8 August 2015.
"E-novinar.com – Новините на едно място" [Mohailova, Tihomria. In 1900 the first electric lamp lit the streets of Sofia. Novinar]. novinar.bg (in Bulgarian). 12 March 2014. Archived from the original on 18 June 2016. Retrieved 22 December 2016.
L. Ivanov. 1991 Sofia street naming proposal. Archived 25 October 2017 at the Wayback Machine Sofia City Place-names Commission, 22 January 1991.
2011 census, Sofia-capital (PDF) (23 ed.). Sofia: National Statistical Institute of Bulgaria. 2012. p. 37 40 43 68 71 74 99 117 132 190 193 196. Archived from the original (PDF) on 15 February 2016.
"National parks in the world" (in Bulgarian). journey.bg. Archived from the original on 23 May 2008. Retrieved 24 May 2008.
"District Mayors". Sofia Municipality. Archived from the original on 20 December 2009. Retrieved 26 December 2009.
""Триъгълникът на властта" или Ларгото: Как се е променял през годините" [The Triangle of Power or The Largo: How It Changed Throughout the Years]. Bulgarian National Television. Archived from the original on 6 June 2020. Retrieved 1 November 2018.
"Как ще изглежда новата пленарна зала на българските депутати?" [What will the new Parliament hall look like?]. Bulgarian National Television. 2 October 2018. Archived from the original on 29 May 2021. Retrieved 1 November 2018.
"Народното събрание – музей?" [The National Assembly – a Museum?]. BTV Novinite. 7 October 2018. Archived from the original on 8 October 2018. Retrieved 1 November 2018.
"РЕШЕНИЕ № 4149-НС София, 27.01.2017" [Resolution No. 4149-NS Sofia]. Central Electoral Commission. 27 January 2017. Archived from the original on 4 April 2019. Retrieved 1 November 2018.
Chalabi, Mona (30 November 2012). "Where are world's deadliest major cities?". theguardian.com. Archived from the original on 23 January 2017. Retrieved 25 September 2016.
David Coulby; Robert Cowen; Crispin Jones (17 January 2013). World Yearbook of Education 2000: Education in Times of Transition. Routledge. p. 10. ISBN 978-1-136-16603-7. Archived from the original on 18 April 2016. Retrieved 29 October 2015. crime rates have exploded in Sofia as well as in Moscow and St Petersburg.
Gergana Noutcheva (26 July 2012). European Foreign Policy and the Challenges of Balkan Accession: Conditionality, legitimacy and compliance. Routledge. p. 192. ISBN 978-1-136-30619-8. Archived from the original on 18 April 2016. Retrieved 29 October 2015. The strongest EU demand – structural changes of the judicial system – had to do with the crime rate in Bulgaria and the apparent impotence of the authorities in Sofia to convict any of the murderes in the high-profile mafia killings that shook the country in 2003–2005.
"Bulgarian Crime – Where killing is a habit". The Economist. 27 October 2005. Archived from the original on 29 June 2015. Retrieved 21 October 2015.
"BBC NEWS – Europe – Romania and Bulgaria join the EU". bbc.co.uk. Archived from the original on 29 May 2021. Retrieved 25 September 2016.
"Bulgaria 2015 Crime and Safety Report". 29 December 2016. Archived from the original on 29 December 2016.
Crime Rates in Bulgaria's Sofia on the Rise Archived 22 May 2015 at the Wayback Machine Novinite
"The Most Dangerous Cities in Europe". Business Insider Inc. Archived from the original on 2 July 2015. Retrieved 23 October 2015.
"Crime in Sofia. Safety in Sofia". Archived from the original on 19 September 2015. Retrieved 21 October 2015.
The prison in Sofia Archived 4 March 2016 at the Wayback Machine. Gdin
"Само 10 000 в затвора, 7000 от тях са цигани". 24chasa.bg. Archived from the original on 24 November 2015. Retrieved 11 April 2018.
"UPDATE: Stallone Returning to NU BOYANA Film Studios in Bulgaria for 'Rambo 5'". Novinite. 30 August 2018. Archived from the original on 31 August 2018. Retrieved 28 October 2018.
"London Has Fallen: Company Credits". IMDb.com. Archived from the original on 27 January 2017. Retrieved 28 October 2018.
"(source)". Archived from the original on 16 August 2016. Retrieved 16 July 2016.
"Колекции – НИМ". Historymuseum.org. Archived from the original on 17 February 2015. Retrieved 11 April 2018.
"Funds and collections". SS. Cyril and Methodius National Library. Archived from the original on 28 October 2018. Retrieved 28 October 2018.
Ecker, Gerhard (1984). Bulgarien. Kunstdenkmäler aus vier Jahrtausenden von den Thrakern bis zur Gegenwart (in German). Köln: DuMont Buchverlag. ISBN 9783406398667. Archived from the original on 20 August 2020. Retrieved 12 September 2017.
"BVA-News". balkanvolleyball.org. Archived from the original on 20 February 2008. Retrieved 11 May 2008.
"Тенис Клуб Малееви". maleevaclub.com. Archived from the original on 14 March 2008. Retrieved 11 May 2008.
"Skate rinks in Sofia". kunki.org. Archived from the original on 17 April 2008. Retrieved 11 May 2008.
"Journey.bg — History of the Sofia velodrome". journey.bg. Archived from the original on 15 May 2005. Retrieved 11 May 2008.
"Swimming pools in Sofia (including Spa centers)". tonus.tialoto.bg. Archived from the original on 10 May 2008. Retrieved 11 May 2008.
"Archived copy" (PDF). Archived from the original (PDF) on 6 July 2011. Retrieved 14 February 2010.{{cite web}}: CS1 maint: archived copy as title (link)
"Population | National statistical institute". www.nsi.bg. Archived from the original on 26 October 2018. Retrieved 31 October 2018.
"Population". nsi.bg. National Statistical Institute of Bulgaria, 2011. Archived from the original on 3 March 2016. Retrieved 12 February 2016.
"Ромите са изолирани от бума в заетостта на Балканите". Mediapool.bg. 11 December 2007. Archived from the original on 6 July 2011. Retrieved 11 April 2018.
"Population and Demographic Processes in 2014 (Final data) – National statistical institute". Nsi.bg. Archived from the original on 15 November 2016. Retrieved 11 April 2018.
"The World According to GaWC 2020". GaWC - Research Network. Globalization and World Cities. Archived from the original on 24 August 2020. Retrieved 31 August 2020.
"The Global Financial Centres Index 27" (PDF). Long Finance. March 2020. Archived (PDF) from the original on 28 March 2020. Retrieved 3 September 2020.
"Sofia ranks 30th in GDP/capita, employment growth 2013–2014 global report". seenews.com. Archived from the original on 21 June 2015. Retrieved 22 January 2015.
"Global Metro Monitor An Uncertain recovery" (PDF). brookings.edu. Archived (PDF) from the original on 2 April 2015. Retrieved 22 January 2015.
"10 Top Cities Around The World To Launch Your Startup". Forbes. 29 November 2015. Archived from the original on 14 March 2016. Retrieved 13 March 2016.
"Regional gross domestic product (PPS per inhabitant at current market prices), by NUTS 3 regions". Eurostat. Archived from the original on 11 April 2016. Retrieved 12 March 2017.
"GDP by Economic Sector and Region". National Statistical Institute. Archived from the original on 16 July 2020. Retrieved 14 July 2020.
"Average monthly wages and salaries of the employees under labour contract by statistical regions and districts". National Statistical Institute. Archived from the original on 7 June 2020. Retrieved 14 July 2020.
"Kapital Quarterly". Sofiaecho.com. Archived from the original on 10 June 2016. Retrieved 11 April 2018.
"IT Sector in Sofia". Invest Sofia. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Coca-Cola Opens Its 2nd Largest Globally IT Center in Sofia". Invest Sofia. 9 June 2018. Archived from the original on 16 July 2020. Retrieved 14 July 2020.
"Ubisoft Sofia". www.ubisoft.com. Archived from the original on 15 August 2022. Retrieved 13 August 2022.
"Hewlett-Packard Bulgaria". Business Park Sofia. Archived from the original on 17 July 2020. Retrieved 14 July 2020.
"VMware to invest €23M and Grow the Site in Sofia to over 1500 People". Invest Sofia. 7 May 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Bosch Group Officially Opened its New Office in Sofia". Invest Sofia. 25 June 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Financial Times Expands Its Team in Sofia". Invest Sofia. 2 July 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"The Software Company Experian Opened its New Office Building in Sofia". Invest Sofia. 8 June 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"IT Manufacturing in Sofia". Invest Sofia. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"American Control System Solutions Manufacturer Woodward Opens Production in Sofia". Invest Sofia. 27 February 2017. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Festo to Invest 25.6 mln. Euro in a New Production Unit in Sofia/". Invest Sofia. 7 June 2018. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Products". Visteon Electronics Bulgaria. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Melexis to Invest €75M to Expand Its Operations in Bulgaria". Invest Sofia. 25 June 2019. Archived from the original on 14 July 2020. Retrieved 14 July 2020.
"Lufthansa Technik Sofia invests 30 mln euro to expand its facilities". SIPA Group. Archived from the original on 16 July 2020. Retrieved 14 July 2020.
Sofia infrastructure from the official website of the Municipality Archived 28 May 2008 at the Wayback Machine (in Bulgarian)
"Sofia (capital)". National Statistical Institute regional statistics. 11 February 2013. Archived from the original on 14 November 2013. Retrieved 17 October 2013.
"Passengers 2018-2019" (PDF). Sofia Airport. Archived (PDF) from the original on 9 June 2020. Retrieved 14 July 2020.
"History of the bus network in Sofia". Sofiatraffic.bg. Archived from the original on 27 August 2013. Retrieved 30 August 2012.
"History of the tramway network in Sofia". Sofiatraffic.bg. Archived from the original on 30 June 2016. Retrieved 30 August 2012.
"History of the trolleybus network in Sofia". Sofiatraffic.bg. 14 February 1941. Archived from the original on 27 August 2013. Retrieved 30 August 2012.)
"Public transport Sofia — official website" (in Bulgarian). sumc.bg. Archived from the original on 29 May 2021. Retrieved 24 May 2008.
"Transport Company Bulgaria— official website" (in Bulgarian). dak-transport.com. Archived from the original on 7 September 2009. Retrieved 21 August 2009.
"Българска национална телевизия – Новини (Bulgarian National Television – News)" (in Bulgarian). bnt.bg. Archived from the original on 3 September 2012. Retrieved 2 September 2012.
"ОП Транспорт и разширение". Metropolitan.bg. Archived from the original on 14 August 2011. Retrieved 2 May 2018.
"Metropolitan Sofia Web Place". metropolitan.bg. Archived from the original on 1 October 2008. Retrieved 24 May 2008.
"General Scheme". Metropolitan.bg. Archived from the original on 14 May 2013. Retrieved 12 March 2013.
"National Federation of the Taxi Drivers in Bulgaria. Regional Member Sofia". nftvb.com. Archived from the original on 2 June 2008. Retrieved 24 May 2008.
"Shared Electric Vehicles Spark in Sofia Increase by 170". Novinite. 13 March 2019. Archived from the original on 29 March 2019. Retrieved 30 March 2019.
"Fines for bad repair work – 'Dnevnik' newspaper". dnevnik.bg. Archived from the original on 13 January 2009. Retrieved 24 May 2008.
"Register of Higher Schools in Bulgaria". Ministry of Education and Science. Archived from the original on 27 October 2018. Retrieved 27 October 2018.
"History". acs.bg. Archived from the original on 14 June 2018. Retrieved 17 December 2018.
"Кои са най-желаните гимназии в София и кои паралелки останаха празни" [Which high schools in Sofia are the most preferred]. Offnews. 3 July 2018. Archived from the original on 27 October 2018. Retrieved 27 October 2018.
"Bulgarian universities". Webometrics Ranking of World Universities. Archived from the original on 12 November 2017. Retrieved 17 February 2019.
"Official website of the Sofia university — History". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"Sofia University aims to attract more foreign students" (in Bulgarian). Akademika. 14 June 2013. Archived from the original on 20 October 2013. Retrieved 19 October 2013.
"University Faculties". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"Independent structures of SU". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"Faculty of Physics structure". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"University Centres". Sofia University. Archived from the original on 19 October 2013. Retrieved 19 October 2013.
"Bulgaria's Nuclear Institute: New Cyclotron To Become Operational in 2 Years". Novinite. 27 October 2016. Archived from the original on 27 October 2018. Retrieved 27 October 2018.
"MSB – Projects". www.msb.bg. Archived from the original on 28 October 2018. Retrieved 27 October 2018.
Zapryanov, Yoan (22 June 2018). "Малката изчислителна армия на България" [Bulgaria's small computing army] (in Bulgarian). Kapital Daily. Archived from the original on 17 November 2019. Retrieved 15 July 2018.
"Градина "Алжир" – София". opoznai.bg (in Bulgarian). 19 June 2015. Archived from the original on 19 May 2021. Retrieved 19 May 2021.
"Н. пр. д-р Хасан Бармауи, почетен консул на кралство Йордания в България, пред "Труд": Йордания е врата за България към Близкия Изток". trud.bg (in Bulgarian). Trud. 25 February 2020. Archived from the original on 19 May 2021. Retrieved 19 May 2021.
"Sister Cities of Ankara". ankara.bel.tr. Ankara. Archived from the original on 28 April 2013. Retrieved 27 December 2019.
"Cu cine este înfrățit Bucureștiul?". Adevărul (in Romanian). 21 February 2011. Archived from the original on 18 November 2019. Retrieved 18 November 2019.
"HE Prime Minister Presides Over Cabinet Regular Meeting". pressarabia.qa. Press Arabia. 28 November 2012. Archived from the original on 18 October 2020. Retrieved 19 May 2021.
"Перелік міст, з якими Києвом підписані документи про поріднення, дружбу, співробітництво, партнерство" (PDF). kyivcity.gov.ua (in Ukrainian). Kyiv. 15 February 2018. Archived (PDF) from the original on 28 January 2020. Retrieved 19 May 2021.
"Our Sister Cities". sistercitiespgh.org. Sister Cities Association of Pittsburgh. Archived from the original on 19 May 2021. Retrieved 19 May 2021.
"Sofia, Shanghai to become sister cities". bnr.bg. BNR Radio Bulgaria. 23 November 2015. Archived from the original on 27 December 2019. Retrieved 27 December 2019.
"Sofia, Budapest to Cooperate in Culture, Tourism, Economy". Archived from the original on 11 May 2018. Retrieved 11 May 2018.
"Friendship and cooperation agreements". Paris.fr. Archived from the original on 15 October 2013. Retrieved 12 October 2013.
"Acordos de geminação, de cooperação e de amizade". cm-lisboa.pt (in Portuguese). Lisboa. Archived from the original on 31 October 2013. Retrieved 27 December 2019.
"Agreements with cities". madrid.es. Madrid. Archived from the original on 10 June 2020. Retrieved 27 December 2019.
"Partner cities". yerevan.am. Yerevan. Archived from the original on 19 August 2014. Retrieved 27 December 2019.

webometrics.info

"Bulgarian universities". Webometrics Ranking of World Universities. Archived from the original on 12 November 2017. Retrieved 17 February 2019.

worldcat.org

search.worldcat.org

"Metropolitan areas in Europe" (PDF). Der Markt für Wohn- und Wirtschaftsimmobilien in Deutschland Ergebnisse des BBSR-Expertenpanel Immobilienmarkt Nr: 95. ISSN 1868-0097. Archived from the original (PDF) on 15 July 2018. Retrieved 15 July 2018.

yerevan.am

"Partner cities". yerevan.am. Yerevan. Archived from the original on 19 August 2014. Retrieved 27 December 2019.

youtube.com

Environment: Sofia, most polluted capital of Europe (News report). Agence France-Presse. 20 December 2015. Archived from the original on 30 October 2021. Retrieved 26 October 2018.