Coba jelasin Rujukan dari Paus Gregorius II dalam bahasa melayu dong

Ekonomou, Andrew J., Byzantine Rome and the Greek Popes: Eastern Influences on Rome and the Papacy from Gregory the Great to Zacharias, A.D. 590–752 (2007)

Levillain, Philippe, The Papacy: Gaius-Proxies, Routledge (2002)

Treadgold, Warren, A History of the Byzantine State and Society (1997)

Mann, Horace K., The Lives of the Popes in the Early Middle Ages, Vol. I: The Popes Under the Lombard Rule, Part 2, 657–795 (1903)

Bury, John Bagnall, A History of the Later Roman Empire From Arcadius to Irene, Vol. II (1889)