APA (7th ed.) Citation

Riley-Smith, J. S. C. (1987). The crusades: A short history (First published.). The Athlone Press.

Chicago Style (17th ed.) Citation

Riley-Smith, Jonathan Simon Christopher. The Crusades: A Short History. First published. London: The Athlone Press, 1987.

MLA (9th ed.) Citation

Riley-Smith, Jonathan Simon Christopher. The Crusades: A Short History. First published. The Athlone Press, 1987.

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