↑Frieda, Leonie (2013). The deadly sisterhood : a story of women, power and intrigue in the Italian Renaissance, 1427-1527 (yn Saesneg). London: Phoenix. t. 358. ISBN978-0-7538-2844-1.
↑Religion and Society (yn Saesneg). Christian Institute for the Study of Religion and Society. 1971. t. 87.
↑L. Jessie Allen (1903). Albrecht Dürer (yn Saesneg). Methuen. t. 29.