MLA

Columbus, Christopher. Epistola De Insulis De Novo Repertis. 0AD. https://collections.library.yale.edu/catalog/9998983.

APA, 6th edition

Columbus, C. (0 C.E.). Epistola de insulis de novo repertis [Manuscripts, Renaissance Italy 16th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/9998983.