APA (7th ed.) Citation

Runciman, S. (1954). A History of the Crusades. Penguin Books.

Chicago Style (17th ed.) Citation

Runciman, Steven. A History of the Crusades. Penguin Books, 1954.

MLA (8th ed.) Citation

Runciman, Steven. A History of the Crusades. Penguin Books, 1954.

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