В.И. Кулаков, Д.А. Пуляева. "Кaliningrad". Большая российская энциклопедия. Diarkibkan daripada yang asal pada June 7, 2019. Dicapai pada August 4, 2020.
Berger, Stefan (13 May 2010). "How to be Russian with a Difference? Kaliningrad and its German Past". Geopolitics. 15 (2): 345–366. doi:10.1080/14650040903486967. S2CID143378878.
"Об исчислении времени". Официальный интернет-портал правовой информации (dalam bahasa Russian). 3 June 2011. Dicapai pada 19 January 2019.CS1 maint: unrecognized language (link)
Berger, Stefan (13 May 2010). "How to be Russian with a Difference? Kaliningrad and its German Past". Geopolitics. 15 (2): 345–366. doi:10.1080/14650040903486967. S2CID143378878.
spiegel.de
Wiegrefe, Klaus (22 May 2010). Müller von Blumencron, Mathias; Mascolo, Georg (penyunting). "Zeitgeschichte: Historischer Ballast" [Contemporary History: Historical Ballast]. Der Spiegel (dalam bahasa German). Hamburg, Germany: Spiegel-Berlag. ISSN2195-1349. Diarkibkan daripada yang asal pada 14 October 2017.CS1 maint: unrecognized language (link)
В.И. Кулаков, Д.А. Пуляева. "Кaliningrad". Большая российская энциклопедия. Diarkibkan daripada yang asal pada June 7, 2019. Dicapai pada August 4, 2020.
Wiegrefe, Klaus (22 May 2010). Müller von Blumencron, Mathias; Mascolo, Georg (penyunting). "Zeitgeschichte: Historischer Ballast" [Contemporary History: Historical Ballast]. Der Spiegel (dalam bahasa German). Hamburg, Germany: Spiegel-Berlag. ISSN2195-1349. Diarkibkan daripada yang asal pada 14 October 2017.CS1 maint: unrecognized language (link)
Wiegrefe, Klaus (22 May 2010). Müller von Blumencron, Mathias; Mascolo, Georg (penyunting). "Zeitgeschichte: Historischer Ballast" [Contemporary History: Historical Ballast]. Der Spiegel (dalam bahasa German). Hamburg, Germany: Spiegel-Berlag. ISSN2195-1349. Diarkibkan daripada yang asal pada 14 October 2017.CS1 maint: unrecognized language (link)