Jelaskan Catatan dari Kontroversi Penobatan

Blumenthal, Uta-Renate (1988). The Investiture Controversy: Church and Monarchy from the Ninth to the Twelfth Century. University of Pennsylvania Press.

Cantor, Norman F. (1993). The Civilization of the Middle Ages. HarperCollins

Cowdrey, H.E.J. (1998). Pope Gregory VII, 1073–1085. Oxford University Press.

Jolly, Karen Louise. (1997). Tradition & Diversity: Christianity in a World Context to 1500. ME Sharpe.

McCarthy, T. J. H. (2014). Chronicles of the Investiture Contest: Frutolf of Michelsberg and his continuators. Manchester: Manchester Medieval Sources. ISBN 978-0-7190-8470-6.

Metz, René. (1960). What Is Canon Law? Hawthorn Books. New York.

Tellenbach, Gerd (1993). The Western Church from the Tenth to the Early Twelfth Century. Cambridge University Press.