MLA

Josephus, Flavius. Vita. 0AD. https://collections.library.yale.edu/catalog/10269753.

APA, 6th edition

Josephus, F. (0 C.E.). Vita [Manuscripts, Medieval Byzantine Empire 13th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/10269753.