APA (7th ed.) Citation

Keegan, J. (1993). A history of warfare (4. print.). Knopf.

Chicago Style (17th ed.) Citation

Keegan, John. A History of Warfare. 4. print. New York: Knopf, 1993.

MLA (9th ed.) Citation

Keegan, John. A History of Warfare. 4. print. Knopf, 1993.