APA (7th ed.) Citation

Barber, M. (1995). Crusaders and heretics, 12th-14th centuries. Variorum collected studies series.

Chicago Style (17th ed.) Citation

Barber, Malcolm. "Crusaders and Heretics, 12th-14th Centuries." Variorum Collected Studies Series 1995.

MLA (8th ed.) Citation

Barber, Malcolm. "Crusaders and Heretics, 12th-14th Centuries." Variorum Collected Studies Series, 1995.

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