APA-referens (7:e uppl.)

Ralph, P. L. (1997). World civilizations, their history and their culture (9th ed.). W.W. Norton.

Chicago-referens (17:e uppl.)

Ralph, Philip Lee. World Civilizations, Their History and Their Culture. 9th ed. New York: W.W. Norton, 1997.

MLA-referens (8:e uppl.)

Ralph, Philip Lee. World Civilizations, Their History and Their Culture. 9th ed. W.W. Norton, 1997.