APA (7th ed.) Citation

Gwynn, A. (1968). The Twelfth-Century Reform. Gill and Son.

Chicago Style (17th ed.) Citation

Gwynn, Aubrey. The Twelfth-Century Reform. Dublin [etc.]: Gill and Son, 1968.

MLA (9th ed.) Citation

Gwynn, Aubrey. The Twelfth-Century Reform. Gill and Son, 1968.