Book of the Elders: Sayings of the Desert Fathers: The Systematic Collection, 

In due course, these sayings (or apophthegmata) were written down and, later, collected and codified. The earliest attempts to codify tales and sayings are now lost. As the collection grew, they were first organized alphabetically, according to the name of the abba who spoke them, in a major collection known as the Apophthegmata Patrum Alphabetica. A supplementary collection, the Anonymous Apophthegmata, followed. Later, both collections were combined and arranged systematically rather than alphabetically. This collection was created sometime between 500 and 575 and later went through a couple of major revisions, the second of which appeared sometime before 970.