MLA

Franciscanus De Obseruantia. 0AD. https://collections.library.yale.edu/catalog/2041070.

APA, 6th edition

Franciscanus de obseruantia. (0 C.E.). [Church records, Engravings, Illustrations, Intaglio prints, Prints (Visual works)]. https://collections.library.yale.edu/catalog/2041070.