MLA

John, of Damascus, and Saint. Book of Saint Barlaam and Josephat and Other Saints' Lives. 0AD. https://collections.library.yale.edu/catalog/10621933.

APA, 6th edition

John, of D., & S. (0 C.E.). Book of Saint Barlaam and Josephat and other saints' lives [Manuscripts, Medieval Germany 15th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/10621933.