Citazione Stile APA (7a Edizione)

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.

Citazione stile Chigago Style (17a edizione)

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.

Citatione MLA (9a ed.)

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.