APA (7th ed.) Citation

Keene. (2006). World War I. Greenwood Press.

Chicago Style (17th ed.) Citation

Keene. World War I. Westport, Conn: Greenwood Press, 2006.

MLA (8th ed.) Citation

Keene. World War I. Greenwood Press, 2006.

Warning: These citations may not always be 100% accurate.