Andes (English Wikipedia)

Analysis of information sources in references of the Wikipedia article "Andes" in English language version.

refsWebsite

Global rank English rank

17doi.org

2^nd place

15harvard.edu

18^th place

17^th place

6web.archive.org

1^st place

3semanticscholar.org

11^th place

8^th place

3worldcat.org

5^th place

2blueplanetbiomes.org

low place

1dechile.net

3,107^th place

low place

1fao.org

318^th place

411^th place

1rice.edu

3,843^rd place

2,772^nd place

1nih.gov

4^th place

1asu.edu

2,187^th place

1,500^th place

1scielo.cl

3,304^th place

8,230^th place

1lyellcollection.org

6,584^th place

4,241^st place

1ghostarchive.org

32^nd place

21^st place

1core.ac.uk

1,734^th place

1,312^th place

1sciencedirect.com

149^th place

178^th place

1trademap.org

low place

1elsevier.com

610^th place

704^th place

1panda.org

3,515^th place

3,318^th place

1biodiversityhotspots.org

low place

1zoom-maps.com

low place

1lanacion.com.ar

291^st place

980^th place

1waterlog.info

9,756^th place

7,017^th place

1argentine-embassy-uk.org

low place

1sonami.cl

low place

1cochilco.cl

low place

1ciren.cl

low place

1infobae.com

303^rd place

1,010^th place

1mch.cl

low place

1commodity.com

low place

argentine-embassy-uk.org

"Information on Argentina". Argentine Embassy London.

asu.edu

geomorphology.sese.asu.edu

Isacks, Bryan L. (1988), "Uplift of the Central Andean Plateau and Bending of the Bolivian Orocline" (PDF), Journal of Geophysical Research, 93 (B4): 3211–3231, Bibcode:1988JGR....93.3211I, doi:10.1029/jb093ib04p03211

biodiversityhotspots.org

Tropical Andes Archived 21 August 2010 at the Wayback Machine – biodiversityhotspots.org

blueplanetbiomes.org

"Climate of the Andes". Archived from the original on 14 December 2007. Retrieved 9 December 2007.
"Pants of the Andies". Archived from the original on 15 December 2007. Retrieved 9 December 2007.

ciren.cl

bibliotecadigital.ciren.cl

Villela Olavarría, Daniela; Cantallopts Araya, Jorge (1 May 2017). A 30 años del Plan Aurífero Nacional, una revisión a la minería de oro en Chile (Report) (in Spanish). Vol. DE 08/2017. COCHILCO.

cochilco.cl

COCHILCO (2024). Informe Consumo de Agua en la Minería del Cobre: Actualización al año 2023 (PDF) (Report) (in Spanish). pp. 2–3. Retrieved 4 May 2025.

commodity.com

"Lithium: What Role Does Tesla Play In The Demand For This Precious Metal? - Commodity.com". commodity.com. Retrieved 9 March 2023.

core.ac.uk

Dorbath, L.; Dorbath, C.; Jimenez, E.; Rivera, L. (1991). "Seismicity and tectonic deformation in the Eastern Cordillera and the sub-Andean zone of central Peru" (PDF). Journal of South American Earth Sciences. 4 (1–2): 13–24. Bibcode:1991JSAES...4...13D. doi:10.1016/0895-9811(91)90015-D.

dechile.net

etimologias.dechile.net

"Cordillera". etimologias.dechile.net. Retrieved 27 December 2015.

doi.org

Miller, Meghan S.; Levander, Alan; Niu, Fenglin; Li, Aibing (23 June 2008). "Upper mantle structure beneath the Caribbean-South American plate boundary from surface wave tomography" (PDF). Journal of Geophysical Research. 114 (B1): B01312. Bibcode:2009JGRB..114.1312M. doi:10.1029/2007JB005507. Archived from the original (PDF) on 5 June 2010. Retrieved 21 November 2010.
Lamb, Simon; Davis, Paul (2003). "Cenozoic climate change as a possible cause for the rise of the Andes". Nature. 425 (6960): 792–797. Bibcode:2003Natur.425..792L. doi:10.1038/nature02049. PMID 14574402. S2CID 4354886.
Isacks, Bryan L. (1988), "Uplift of the Central Andean Plateau and Bending of the Bolivian Orocline" (PDF), Journal of Geophysical Research, 93 (B4): 3211–3231, Bibcode:1988JGR....93.3211I, doi:10.1029/jb093ib04p03211
Kley, J. (1999), "Geologic and geometric constraints on a kinematic model of the Bolivian orocline", Journal of South American Earth Sciences, 12 (2): 221–235, Bibcode:1999JSAES..12..221K, doi:10.1016/s0895-9811(99)00015-2
Beck, Myrl E. (1987), "Tectonic rotations on the leading edge of South America: The Bolivian orocline revisited", Geology, 15 (9): 806–808, Bibcode:1987Geo....15..806B, doi:10.1130/0091-7613(1987)15<806:trotle>2.0.co;2
Prezzi, Claudia B.; Vilas, Juan F. (1998). "New evidence of clockwise vertical axis rotations south of the Arica elbow (Argentine Puna)". Tectonophysics. 292 (1): 85–100. Bibcode:1998Tectp.292...85P. doi:10.1016/s0040-1951(98)00058-4.
Santos, J.O.S.; Rizzotto, G.J.; Potter, P.E.; McNaughton, N.J.; Matos, R.S.; Hartmann, L.A.; Chemale Jr., F.; Quadros, M.E.S. (2008). "Age and autochthonous evolution of the Sunsás Orogen in West Amazon Craton based on mapping and U–Pb geochronology". Precambrian Research. 165 (3–4): 120–152. Bibcode:2008PreR..165..120S. doi:10.1016/j.precamres.2008.06.009.
Rapela, C.W.; Pankhurst, R.J; Casquet, C.; Baldo, E.; Saavedra, J.; Galindo, C.; Fanning, C.M. (1998). "The Pampean Orogeny of the southern proto-Andes: Cambrian continental collision in the Sierras de Córdoba" (PDF). In Pankhurst, R.J; Rapela, C.W. (eds.). The Proto-Andean Margin of Gondwana. Geological Society, London, Special Publications. Vol. 142. pp. 181–217. doi:10.1144/GSL.SP.1998.142.01.10. S2CID 128814617. Archived (PDF) from the original on 9 October 2022. Retrieved 7 December 2015.
Wilson, T.J. (1991). "Transition from back-arc to foreland basin development in the southernmost Andes: Stratigraphic record from the Ultima Esperanza District, Chile". Geological Society of America Bulletin. 103 (1): 98–111. Bibcode:1991GSAB..103...98W. doi:10.1130/0016-7606(1991)103<0098:tfbatf>2.3.co;2.
Rodriguez Piceda, Constanza; Gao, Ya-Jian; Cacace, Mauro; Scheck-Wenderoth, Magdalena; Bott, Judith; Strecker, Manfred; Tilmann, Frederik (17 March 2023). "The influence of mantle hydration and flexure on slab seismicity in the southern Central Andes". Communications Earth & Environment. 4 (1): 79. Bibcode:2023ComEE...4...79R. doi:10.1038/s43247-023-00729-1. ISSN 2662-4435.
Dorbath, L.; Dorbath, C.; Jimenez, E.; Rivera, L. (1991). "Seismicity and tectonic deformation in the Eastern Cordillera and the sub-Andean zone of central Peru" (PDF). Journal of South American Earth Sciences. 4 (1–2): 13–24. Bibcode:1991JSAES...4...13D. doi:10.1016/0895-9811(91)90015-D.
Suárez, Gerardo; Molnar, Peter; Burchfiel, B. Clark (1983). "Seismicity, fault plane solutions, depth of faulting, and active tectonics of the Andes of Peru, Ecuador, and southern Colombia". Journal of Geophysical Research: Solid Earth. 88 (B12): 10403–10428. Bibcode:1983JGR....8810403S. doi:10.1029/JB088iB12p10403.
González-Maurel, Osvaldo; le Roux, Petrus; Godoy, Benigno; Troll, Valentin R.; Deegan, Frances M.; Menzies, Andrew (15 November 2019). "The great escape: Petrogenesis of low-silica volcanism of Pliocene to Quaternary age associated with the Altiplano-Puna Volcanic Complex of northern Chile (21°10′–22°50′S)". Lithos. 346–347: 105162. Bibcode:2019Litho.34605162G. doi:10.1016/j.lithos.2019.105162. ISSN 0024-4937. S2CID 201291787.
Armijo, Rolando; Lacassin, Robin; Coudurier-Curveur, Aurélie; Carrizo, Daniel (1 April 2015). "Coupled tectonic evolution of Andean orogeny and global climate". Earth-Science Reviews. 143: 1–35. Bibcode:2015ESRv..143....1A. doi:10.1016/j.earscirev.2015.01.005. ISSN 0012-8252.
Kuhle, M (2011). "The High-Glacial (Last Glacial Maximum) Glacier Cover of the Aconcagua Group and Adjacent Massifs in the Mendoza Andes (South America) with a Closer Look at Further Empirical Evidence". In Ehlers, J; Gibbard, PL; Hughes, PD (eds.). Quaternary Glaciation – Extent and Chronology, A Closer Look. Developments in Quaternary Sciences. Vol. 15. Amsterdam: Elsevier B.V. pp. 735–738. Bibcode:2011DevQS..15..735K. doi:10.1016/B978-0-444-53447-7.00053-2. ISBN 978-0-444-53447-7.
Brüggen, J (1929). "Zur Glazialgeologie der chilenischen". Anden. Geol. Rundsch. (in German). 20. Berlin: 1–35. doi:10.1007/BF01805072.
Kuhle, M (2004). "The Last Glacial Maximum (LGM) glacier cover of the Aconcagua group and adjacent massifs in the Mendoza Andes (South America)". In Ehlers, J; Gibbard, PL (eds.). Quaternary Glaciation— Extent and Chronology. Part III: South America, Asia, Africa, Australia, Antarctica. Developments in Quaternary Sciences. Vol. 2c. Amsterdam: Elsevier B.V. pp. 75–81. Bibcode:2004DevQS...2...75K. doi:10.1016/S1571-0866(04)80113-1. ISBN 978-0-444-51593-3.

elsevier.com

linkinghub.elsevier.com

Armijo, Rolando; Lacassin, Robin; Coudurier-Curveur, Aurélie; Carrizo, Daniel (1 April 2015). "Coupled tectonic evolution of Andean orogeny and global climate". Earth-Science Reviews. 143: 1–35. Bibcode:2015ESRv..143....1A. doi:10.1016/j.earscirev.2015.01.005. ISSN 0012-8252.

fao.org

"Mountains, biodiversity and conservation". Food and Agriculture Organization. Retrieved 28 January 2019.

ghostarchive.org

Rapela, C.W.; Pankhurst, R.J; Casquet, C.; Baldo, E.; Saavedra, J.; Galindo, C.; Fanning, C.M. (1998). "The Pampean Orogeny of the southern proto-Andes: Cambrian continental collision in the Sierras de Córdoba" (PDF). In Pankhurst, R.J; Rapela, C.W. (eds.). The Proto-Andean Margin of Gondwana. Geological Society, London, Special Publications. Vol. 142. pp. 181–217. doi:10.1144/GSL.SP.1998.142.01.10. S2CID 128814617. Archived (PDF) from the original on 9 October 2022. Retrieved 7 December 2015.

harvard.edu

ui.adsabs.harvard.edu

Miller, Meghan S.; Levander, Alan; Niu, Fenglin; Li, Aibing (23 June 2008). "Upper mantle structure beneath the Caribbean-South American plate boundary from surface wave tomography" (PDF). Journal of Geophysical Research. 114 (B1): B01312. Bibcode:2009JGRB..114.1312M. doi:10.1029/2007JB005507. Archived from the original (PDF) on 5 June 2010. Retrieved 21 November 2010.
Lamb, Simon; Davis, Paul (2003). "Cenozoic climate change as a possible cause for the rise of the Andes". Nature. 425 (6960): 792–797. Bibcode:2003Natur.425..792L. doi:10.1038/nature02049. PMID 14574402. S2CID 4354886.
Isacks, Bryan L. (1988), "Uplift of the Central Andean Plateau and Bending of the Bolivian Orocline" (PDF), Journal of Geophysical Research, 93 (B4): 3211–3231, Bibcode:1988JGR....93.3211I, doi:10.1029/jb093ib04p03211
Kley, J. (1999), "Geologic and geometric constraints on a kinematic model of the Bolivian orocline", Journal of South American Earth Sciences, 12 (2): 221–235, Bibcode:1999JSAES..12..221K, doi:10.1016/s0895-9811(99)00015-2
Beck, Myrl E. (1987), "Tectonic rotations on the leading edge of South America: The Bolivian orocline revisited", Geology, 15 (9): 806–808, Bibcode:1987Geo....15..806B, doi:10.1130/0091-7613(1987)15<806:trotle>2.0.co;2
Prezzi, Claudia B.; Vilas, Juan F. (1998). "New evidence of clockwise vertical axis rotations south of the Arica elbow (Argentine Puna)". Tectonophysics. 292 (1): 85–100. Bibcode:1998Tectp.292...85P. doi:10.1016/s0040-1951(98)00058-4.
Santos, J.O.S.; Rizzotto, G.J.; Potter, P.E.; McNaughton, N.J.; Matos, R.S.; Hartmann, L.A.; Chemale Jr., F.; Quadros, M.E.S. (2008). "Age and autochthonous evolution of the Sunsás Orogen in West Amazon Craton based on mapping and U–Pb geochronology". Precambrian Research. 165 (3–4): 120–152. Bibcode:2008PreR..165..120S. doi:10.1016/j.precamres.2008.06.009.
Wilson, T.J. (1991). "Transition from back-arc to foreland basin development in the southernmost Andes: Stratigraphic record from the Ultima Esperanza District, Chile". Geological Society of America Bulletin. 103 (1): 98–111. Bibcode:1991GSAB..103...98W. doi:10.1130/0016-7606(1991)103<0098:tfbatf>2.3.co;2.
Rodriguez Piceda, Constanza; Gao, Ya-Jian; Cacace, Mauro; Scheck-Wenderoth, Magdalena; Bott, Judith; Strecker, Manfred; Tilmann, Frederik (17 March 2023). "The influence of mantle hydration and flexure on slab seismicity in the southern Central Andes". Communications Earth & Environment. 4 (1): 79. Bibcode:2023ComEE...4...79R. doi:10.1038/s43247-023-00729-1. ISSN 2662-4435.
Dorbath, L.; Dorbath, C.; Jimenez, E.; Rivera, L. (1991). "Seismicity and tectonic deformation in the Eastern Cordillera and the sub-Andean zone of central Peru" (PDF). Journal of South American Earth Sciences. 4 (1–2): 13–24. Bibcode:1991JSAES...4...13D. doi:10.1016/0895-9811(91)90015-D.
Suárez, Gerardo; Molnar, Peter; Burchfiel, B. Clark (1983). "Seismicity, fault plane solutions, depth of faulting, and active tectonics of the Andes of Peru, Ecuador, and southern Colombia". Journal of Geophysical Research: Solid Earth. 88 (B12): 10403–10428. Bibcode:1983JGR....8810403S. doi:10.1029/JB088iB12p10403.
González-Maurel, Osvaldo; le Roux, Petrus; Godoy, Benigno; Troll, Valentin R.; Deegan, Frances M.; Menzies, Andrew (15 November 2019). "The great escape: Petrogenesis of low-silica volcanism of Pliocene to Quaternary age associated with the Altiplano-Puna Volcanic Complex of northern Chile (21°10′–22°50′S)". Lithos. 346–347: 105162. Bibcode:2019Litho.34605162G. doi:10.1016/j.lithos.2019.105162. ISSN 0024-4937. S2CID 201291787.
Armijo, Rolando; Lacassin, Robin; Coudurier-Curveur, Aurélie; Carrizo, Daniel (1 April 2015). "Coupled tectonic evolution of Andean orogeny and global climate". Earth-Science Reviews. 143: 1–35. Bibcode:2015ESRv..143....1A. doi:10.1016/j.earscirev.2015.01.005. ISSN 0012-8252.
Kuhle, M (2011). "The High-Glacial (Last Glacial Maximum) Glacier Cover of the Aconcagua Group and Adjacent Massifs in the Mendoza Andes (South America) with a Closer Look at Further Empirical Evidence". In Ehlers, J; Gibbard, PL; Hughes, PD (eds.). Quaternary Glaciation – Extent and Chronology, A Closer Look. Developments in Quaternary Sciences. Vol. 15. Amsterdam: Elsevier B.V. pp. 735–738. Bibcode:2011DevQS..15..735K. doi:10.1016/B978-0-444-53447-7.00053-2. ISBN 978-0-444-53447-7.
Kuhle, M (2004). "The Last Glacial Maximum (LGM) glacier cover of the Aconcagua group and adjacent massifs in the Mendoza Andes (South America)". In Ehlers, J; Gibbard, PL (eds.). Quaternary Glaciation— Extent and Chronology. Part III: South America, Asia, Africa, Australia, Antarctica. Developments in Quaternary Sciences. Vol. 2c. Amsterdam: Elsevier B.V. pp. 75–81. Bibcode:2004DevQS...2...75K. doi:10.1016/S1571-0866(04)80113-1. ISBN 978-0-444-51593-3.

infobae.com

Villantoy Gómez, Abigail (24 May 2024). "Pallaqueras: la actividad femenina poco conocida donde se trabaja seleccionando manualmente rocas con metales preciosos". Infobae (in Spanish). Retrieved 1 March 2025.

lanacion.com.ar

"Jujuy apuesta a captar las cargas de Brasil en tránsito hacia Chile by Emiliano Galli". La Nación. La Nación newspaper. 7 August 2009. Retrieved 22 July 2011.

lyellcollection.org

sp.lyellcollection.org

Rapela, C.W.; Pankhurst, R.J; Casquet, C.; Baldo, E.; Saavedra, J.; Galindo, C.; Fanning, C.M. (1998). "The Pampean Orogeny of the southern proto-Andes: Cambrian continental collision in the Sierras de Córdoba" (PDF). In Pankhurst, R.J; Rapela, C.W. (eds.). The Proto-Andean Margin of Gondwana. Geological Society, London, Special Publications. Vol. 142. pp. 181–217. doi:10.1144/GSL.SP.1998.142.01.10. S2CID 128814617. Archived (PDF) from the original on 9 October 2022. Retrieved 7 December 2015.

mch.cl

La mina eléctrica: Cómo la minería enfrenta el reto de las condiciones ambientales

nih.gov

pubmed.ncbi.nlm.nih.gov

Lamb, Simon; Davis, Paul (2003). "Cenozoic climate change as a possible cause for the rise of the Andes". Nature. 425 (6960): 792–797. Bibcode:2003Natur.425..792L. doi:10.1038/nature02049. PMID 14574402. S2CID 4354886.

panda.org

wwf.panda.org

"Tropical and Subtropical Dry Broadleaf Forest Ecoregions". wwf.panda.org. Archived from the original on 25 April 2012. Retrieved 27 December 2015.

rice.edu

gseis.rice.edu

Miller, Meghan S.; Levander, Alan; Niu, Fenglin; Li, Aibing (23 June 2008). "Upper mantle structure beneath the Caribbean-South American plate boundary from surface wave tomography" (PDF). Journal of Geophysical Research. 114 (B1): B01312. Bibcode:2009JGRB..114.1312M. doi:10.1029/2007JB005507. Archived from the original (PDF) on 5 June 2010. Retrieved 21 November 2010.

scielo.cl

Arriagada, César; Ferrando, Rodolfo; Córdova, Loreto; Morata, Diego; Roperch, Pierrick (2013), "The Maipo Orocline: A first scale structural feature in the Miocene to Recent geodynamic evolution in the central Chilean Andes" (PDF), Andean Geology, 40 (3): 419–437

sciencedirect.com

González-Maurel, Osvaldo; le Roux, Petrus; Godoy, Benigno; Troll, Valentin R.; Deegan, Frances M.; Menzies, Andrew (15 November 2019). "The great escape: Petrogenesis of low-silica volcanism of Pliocene to Quaternary age associated with the Altiplano-Puna Volcanic Complex of northern Chile (21°10′–22°50′S)". Lithos. 346–347: 105162. Bibcode:2019Litho.34605162G. doi:10.1016/j.lithos.2019.105162. ISSN 0024-4937. S2CID 201291787.

semanticscholar.org

api.semanticscholar.org

Lamb, Simon; Davis, Paul (2003). "Cenozoic climate change as a possible cause for the rise of the Andes". Nature. 425 (6960): 792–797. Bibcode:2003Natur.425..792L. doi:10.1038/nature02049. PMID 14574402. S2CID 4354886.
Rapela, C.W.; Pankhurst, R.J; Casquet, C.; Baldo, E.; Saavedra, J.; Galindo, C.; Fanning, C.M. (1998). "The Pampean Orogeny of the southern proto-Andes: Cambrian continental collision in the Sierras de Córdoba" (PDF). In Pankhurst, R.J; Rapela, C.W. (eds.). The Proto-Andean Margin of Gondwana. Geological Society, London, Special Publications. Vol. 142. pp. 181–217. doi:10.1144/GSL.SP.1998.142.01.10. S2CID 128814617. Archived (PDF) from the original on 9 October 2022. Retrieved 7 December 2015.
González-Maurel, Osvaldo; le Roux, Petrus; Godoy, Benigno; Troll, Valentin R.; Deegan, Frances M.; Menzies, Andrew (15 November 2019). "The great escape: Petrogenesis of low-silica volcanism of Pliocene to Quaternary age associated with the Altiplano-Puna Volcanic Complex of northern Chile (21°10′–22°50′S)". Lithos. 346–347: 105162. Bibcode:2019Litho.34605162G. doi:10.1016/j.lithos.2019.105162. ISSN 0024-4937. S2CID 201291787.

sonami.cl

Distritos productivos para el desarrollo de la minería chilena [Productive districts for the development of mining in Chile] (Report) (in Spanish). Centro de Estudios y Documentación Mineros de SONAMI. 2025.

trademap.org

"Trade Map - List of exporters for the selected product in 2023 (Copper ores and concentrates)". www.trademap.org. Retrieved 17 August 2024.

waterlog.info

W. van Immerzeel, 1989. Irrigation and erosion/flood control at high altitudes in the Andes. Published in Annual Report 1989, pp. 8–24, International Institute for Land Reclamation and Improvement, Wageningen, The Netherlands. On line: [1]

web.archive.org

Miller, Meghan S.; Levander, Alan; Niu, Fenglin; Li, Aibing (23 June 2008). "Upper mantle structure beneath the Caribbean-South American plate boundary from surface wave tomography" (PDF). Journal of Geophysical Research. 114 (B1): B01312. Bibcode:2009JGRB..114.1312M. doi:10.1029/2007JB005507. Archived from the original (PDF) on 5 June 2010. Retrieved 21 November 2010.
"Climate of the Andes". Archived from the original on 14 December 2007. Retrieved 9 December 2007.
"Tropical and Subtropical Dry Broadleaf Forest Ecoregions". wwf.panda.org. Archived from the original on 25 April 2012. Retrieved 27 December 2015.
Tropical Andes Archived 21 August 2010 at the Wayback Machine – biodiversityhotspots.org
"Pants of the Andies". Archived from the original on 15 December 2007. Retrieved 9 December 2007.
"Andes travel map". Archived from the original on 24 September 2010. Retrieved 20 June 2010.

worldcat.org

search.worldcat.org

Rodriguez Piceda, Constanza; Gao, Ya-Jian; Cacace, Mauro; Scheck-Wenderoth, Magdalena; Bott, Judith; Strecker, Manfred; Tilmann, Frederik (17 March 2023). "The influence of mantle hydration and flexure on slab seismicity in the southern Central Andes". Communications Earth & Environment. 4 (1): 79. Bibcode:2023ComEE...4...79R. doi:10.1038/s43247-023-00729-1. ISSN 2662-4435.
González-Maurel, Osvaldo; le Roux, Petrus; Godoy, Benigno; Troll, Valentin R.; Deegan, Frances M.; Menzies, Andrew (15 November 2019). "The great escape: Petrogenesis of low-silica volcanism of Pliocene to Quaternary age associated with the Altiplano-Puna Volcanic Complex of northern Chile (21°10′–22°50′S)". Lithos. 346–347: 105162. Bibcode:2019Litho.34605162G. doi:10.1016/j.lithos.2019.105162. ISSN 0024-4937. S2CID 201291787.
Armijo, Rolando; Lacassin, Robin; Coudurier-Curveur, Aurélie; Carrizo, Daniel (1 April 2015). "Coupled tectonic evolution of Andean orogeny and global climate". Earth-Science Reviews. 143: 1–35. Bibcode:2015ESRv..143....1A. doi:10.1016/j.earscirev.2015.01.005. ISSN 0012-8252.

zoom-maps.com

andes.zoom-maps.com

"Andes travel map". Archived from the original on 24 September 2010. Retrieved 20 June 2010.