APA (7th ed.) Citation

Keegan, J. (2003). Who's who in World War II. Routledge.

Chicago Style (17th ed.) Citation

Keegan, John. Who's Who in World War II. London: Routledge, 2003.

MLA (9th ed.) Citation

Keegan, John. Who's Who in World War II. Routledge, 2003.