MLA

Calendar; Martyrology; Benedictine Rule. 0AD. https://collections.library.yale.edu/catalog/2013561.

APA, 6th edition

Calendar; Martyrology; Benedictine Rule. (0 C.E.). [Manuscripts, Medieval France 12th century, Manuscripts, Medieval France 14th century, Manuscripts, Medieval France 15th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/2013561.