MLA

Pseudo-Dionysius, the Areopagite. De Ecclesiastica Hierarchia. 0AD. https://collections.library.yale.edu/catalog/11403238.

APA, 6th edition

Pseudo-Dionysius, the A. (0 C.E.). De ecclesiastica hierarchia [Early works to 1800, Translations, Manuscripts, Renaissance Germany 16th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/11403238.