APA (7th ed.) Citation

Duggan, A. (1964). The story of the Crusades, 1097-1291. Pantheon Books.

Chicago Style (17th ed.) Citation

Duggan, Alfred. The Story of the Crusades, 1097-1291. New York: Pantheon Books, 1964.

MLA (9th ed.) Citation

Duggan, Alfred. The Story of the Crusades, 1097-1291. Pantheon Books, 1964.

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