MLA

Telesphorus, of Cosenza. Libellus. 0AD. https://collections.library.yale.edu/catalog/33291300.

APA, 6th edition

Telesphorus, of C. (0 C.E.). Libellus [Early works to 1800, Manuscripts, Medieval Italy 14th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/33291300.