Library of Congress Country Studies

Bulgaria. Library of Congress Country Studies. 1992 [24 September 2012]. （原始内容存档于2018-12-09）.  The Chervenkov Era. Library of Congress Country Studies. 1992

Union of Soviet Socialist Republics. Encyclopædia Britannica. [2008-08-20].  Library of Congress Country Studies Archive.is的存檔，存档日期2012-12-12

Library of Congress Country Studies. [2014年2月3日]. （原始内容存档于2011年4月30日） （英语）.  The Great War, 1843–52 – Uruguay. Library of Congress Country Studies. [2014年2月3日]

Country Study: Chad. Library of Congress Country Studies. 1990 [2014-02-23]. （原始内容存档于2015-07-06）.  Azevedo, Mario J. Roots of Violence: A History of War

June 2006) Pakistan - Library of Congress Country Studies. [2020-09-29]. （原始内容存档于2012-12-12）.  Library of Congress Country Studies. [2020-09-29]. （原始内容存档于2012-12-13）