MLA

Cantoral, Hieronymus Valentinus de. Confessio Fidei Exhibita Invict. Imp. Carolo V. Caesari Aug. in Comiciis Augustae. 0AD. https://collections.library.yale.edu/catalog/11150261.

APA, 6th edition

Cantoral, H. V. de. (0 C.E.). Confessio fidei exhibita invict. imp. Carolo V. Caesari Aug. in Comiciis Augustae [Manuscripts, Renaissance 16th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/11150261.