21 September 2017 ↑ Platina, Bartolomeo (1479), The Lives of the Popes From The Time Of Our Saviour Jesus Christ to the Accession of Gregory VII, I, London: Griffith Farran & Co., pp. 241–242, retrieved 2013-04-25 ↑ Mann, Horace, K. The Lives of the Popes in the Early Middle Ages, Vol IV: The Popes in the Days of Feudal Anarchy, 891–999.