MLA

Watkins, Carleton E., 1829-1916. The Pasadena, near San Gabriel. Watkins 3. ca. 1880. https://collections.library.yale.edu/catalog/2056990.

APA, 6th edition

Watkins, Carleton E., 1829-1916. (["Watkins 3"])(ca. 1880)[The Pasadena, near San Gabriel]. https://collections.library.yale.edu/catalog/2056990.