Setton, Kenneth Meyer: The Papacy and the Levant, 1204-1571: The fifteenth century. (Memoirs of the American Philosophical Society 127) American Philosophical Society, 1978. ISBN 0871691272Teoksen verkkoversio.
Rousseau, Philip & Papoutsakis, Emmanuel (toim.): Transformations of Late Antiquity: Essays for Peter Brown. (Volume 2) Ashgate Publishing, Ltd., 2009. ISBN 0754665534Teoksen verkkoversio.
stanford.edu
plato.stanford.edu
Ierodiakonou, Katerina & Bydén, Börje: Byzantine PhilosophyThe Stanford Encyclopedia of Philosophy. The Metaphysics Research Lab. Stanford University. Viitattu 11.4.2014. (englanniksi)