MLA

Macrobius, Ambrosius Aurelius Theodosius. Commentum in Somnium Scipionis. 0AD. https://collections.library.yale.edu/catalog/2040654.

APA, 6th edition

Macrobius, A. A. T. (0 C.E.). Commentum in Somnium Scipionis [Early works to 1800, Manuscripts, Medieval Germany 10th century, Medieval and Renaissance Manuscript Fragments in Beinecke Library, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/2040654.