MLA

Decretales (Fragment). 0AD. https://collections.library.yale.edu/catalog/2004047.

APA, 6th edition

Decretales (fragment). (0 C.E.). [Commentaries, Manuscripts, Medieval, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/2004047.