MLA

Ordinarium Missae. 0AD. https://collections.library.yale.edu/catalog/2009732.

APA, 6th edition

Ordinarium Missae. (0 C.E.). [Manuscripts, Medieval Spain 15th century, Manuscripts, Renaissance Spain 15th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/2009732.