MLA

Origen. Peri Archon (De Principiis) (Fragment). 0AD. https://collections.library.yale.edu/catalog/2003585.

APA, 6th edition

O. (0 C.E.). Peri Archon (De principiis) (fragment). [Manuscripts, Medieval Germany 9th century, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/2003585.