MLA

Ascetic and Devotional Treatises; Life of St. John Calybita; Italian Poetry in Praise of the Virgin. 0AD. https://collections.library.yale.edu/catalog/10995121.

APA, 6th edition

Ascetic and devotional treatises; Life of St. John Calybita; Italian poetry in praise of the Virgin. (0 C.E.). [Manuscripts, Medieval Italy 15th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/10995121.