Citazione Stile APA (7a Edizione)

Whitney, D. C., & Whitney, R. V. (1990). The American presidents (7th ed.). Prentice Hall Press.

Citazione stile Chigago Style (17a edizione)

Whitney, David C., e Robin Vaughn Whitney. The American Presidents. 7th ed. New York: Prentice Hall Press, 1990.

Citatione MLA (9a ed.)

Whitney, David C., e Robin Vaughn Whitney. The American Presidents. 7th ed. Prentice Hall Press, 1990.