MLA

Evrard de Béthune. Graecismus (Fragment). 0AD. https://collections.library.yale.edu/catalog/10543828.

APA, 6th edition

Evrard de Béthune. (0 C.E.). Graecismus (fragment). [Manuscripts, Medieval France 14th century, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/10543828.