MLA

Bernard, de Gordon, approximately 1260-approximately 1318. De Pronosticis. [ca. 1400-1425]. https://collections.library.yale.edu/catalog/16371236.

APA, 6th edition

Bernard, de Gordon, approximately 1260-approximately 1318. ([ca. 1400-1425])[De Pronosticis]. https://collections.library.yale.edu/catalog/16371236.