APA (7th ed.) Citation

Gregor, V., & Emerton, E. (1932). The correspondence of pope Gregory VII: Selected letters from the registrum. Records of civilization.

Chicago Style (17th ed.) Citation

Gregor, VII., and Ephraim Emerton. "The Correspondence of Pope Gregory VII: Selected Letters from the Registrum." Records of Civilization 1932.

MLA (8th ed.) Citation

Gregor, VII., and Ephraim Emerton. "The Correspondence of Pope Gregory VII: Selected Letters from the Registrum." Records of Civilization, 1932.

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