MLA

Mrs. Heidelberg Baron Otranto. [Graphic]. A. Hamilton, 0AD. https://collections.library.yale.edu/catalog/10713456.

APA, 6th edition

Mrs. Heidelberg Baron Otranto. [graphic]. (0 C.E.). [Stipple engravings England London 1769, Etchings England London 1769, Portrait prints, Periodical illustrations]. A. Hamilton. https://collections.library.yale.edu/catalog/10713456.