APA (7th ed.) Citation

Keen, M. (1968). A history of Medieval Europe. F. A. Praeger.

Chicago Style (17th ed.) Citation

Keen, Maurice. A History of Medieval Europe. New York: F. A. Praeger, 1968.

MLA (9th ed.) Citation

Keen, Maurice. A History of Medieval Europe. F. A. Praeger, 1968.