MLA

Epistolary. 0AD. https://collections.library.yale.edu/catalog/32470019.

APA, 6th edition

Epistolary. (0 C.E.). [Manuscripts, Medieval Germany 15th century, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/32470019.