Cite

Borromeo, Antonio. 2 letters; (Barcelona?). 6pp.

MLA

Borromeo, Antonio. 2 Letters; (Barcelona?). 6pp. 0AD. https://collections.library.yale.edu/catalog/2065199.

APA, 6th edition

Borromeo, Antonio. 2 letters; (Barcelona?). 6pp. (0 C.E.). https://collections.library.yale.edu/catalog/2065199.