MLA

Gallican Sacramentary. 0AD. https://collections.library.yale.edu/catalog/10269797.

APA, 6th edition

Gallican sacramentary. (0 C.E.). [Manuscripts, Medieval France 8th century, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/10269797.