Works about John Cassian

John Cassian -- from The New Schaff-Herzog Encyclopedia of Religious Knowledge
Catholic Encyclopedia, Volume 3: Brownson-Clairvaux -- from Herbermann, Charles George (1840-1916)
Dictionary of Christian Biography and Literature to the End of the Sixth Century -- from Wace, Henry (1836-1924)
Cassian, John (360-435) -- from Wikipedia Article