Directorium iuris, etc.
MLA
Quesvel, Petrus. Directorium Iuris, Etc. 0AD. https://collections.library.yale.edu/catalog/2052957.
APA, 6th edition
Quesvel, P. (0 C.E.). Directorium iuris, etc. [Annotations, Inhabited initials, Manuscripts, Marginalia]. https://collections.library.yale.edu/catalog/2052957.