MLA

Roman De Tristan (Fragments). 0AD. https://collections.library.yale.edu/catalog/16161079.

APA, 6th edition

Roman de Tristan (fragments). (0 C.E.). [Early works to 1800, 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/16161079.