MLA

Cassian, John, approximately 360-approximately 435. Collationes. [between 1300 and 1400]. https://collections.library.yale.edu/catalog/2004993.

APA, 6th edition

Cassian, John, approximately 360-approximately 435. ([between 1300 and 1400])[Collationes]. https://collections.library.yale.edu/catalog/2004993.