MLA

Avalos, Costanza d', and Marquesa del Vasto. ALS to Paolo Giovio. 0AD. https://collections.library.yale.edu/catalog/10610309.

APA, 6th edition

Avalos, C. d', & del Vasto, M. (0 C.E.). ALS to Paolo Giovio [Manuscripts, Medieval Italy 16th century, Medieval and Renaissance Manuscripts in Beinecke Library]. https://collections.library.yale.edu/catalog/10610309.