APA (7th ed.) Citation

Bullock, A., & Hitler, A. (1991). Hitler: A study in tyranny. Harper Perennial.

Chicago Style (17th ed.) Citation

Bullock, Alan, and Adolf Hitler. Hitler: A Study in Tyranny. New York: Harper Perennial, 1991.

MLA (8th ed.) Citation

Bullock, Alan, and Adolf Hitler. Hitler: A Study in Tyranny. Harper Perennial, 1991.