MLA

Aken, Hein van. Die Rose. 14AD. https://collections.library.yale.edu/catalog/2043579.

APA, 6th edition

Aken, H. van. (14 C.E.). Die rose [Manuscripts, Medieval Flanders (Belgium) 14th century, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/2043579.