APA (7th ed.) Citation

Runciman Sir. (1987). A history of the Crusades. Cambridge University Press.

Chicago Style (17th ed.) Citation

Runciman Sir. A History of the Crusades. Cambridge New York: Cambridge University Press, 1987.

MLA (8th ed.) Citation

Runciman Sir. A History of the Crusades. Cambridge University Press, 1987.