MLA

Antiphonary (Fragment). 0AD. https://collections.library.yale.edu/catalog/2004128.

APA, 6th edition

Antiphonary (fragment). (0 C.E.). [Manuscripts, Medieval Italy 15th century, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/2004128.