MLA

The Portraiture of the Illustreous Princesse Frances Duchess of Richmond and Lenox ... [Graphic]. publisher not identified, 0AD. https://collections.library.yale.edu/catalog/16729737.

APA, 6th edition

The portraiture of the illustreous Princesse Frances Duchess of Richmond and Lenox ... [graphic]. (0 C.E.). [Portrait prints, Engravings England London 1750, Stipple engravings England London 1750, Etchings England London 1750]. publisher not identified. https://collections.library.yale.edu/catalog/16729737.