MLA

Priscian, active approximately 500-530. Grammatica minor. [between 1175 and 1200]. https://collections.library.yale.edu/catalog/10190028.

APA, 6th edition

Priscian, active approximately 500-530. ([between 1175 and 1200])[Grammatica minor]. https://collections.library.yale.edu/catalog/10190028.