United States Library of Congress. (1933). Classification. Class D: Universal and old world history. European War D501-725 (2nd ed. as in force August 1933.). U. S. Government Printing Office.
Chicago-viite (17. p.)United States Library of Congress. Classification. Class D: Universal and Old World History. European War D501-725. 2nd ed. as in force August 1933. Washington: U. S. Government Printing Office, 1933.
MLA-viite (9. p.)United States Library of Congress. Classification. Class D: Universal and Old World History. European War D501-725. 2nd ed. as in force August 1933. U. S. Government Printing Office, 1933.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.