MLA

A Rum Letter to a Rum Duke on a Rum Occasion [Graphic]. E. Sumpter, 0AD. https://collections.library.yale.edu/catalog/10713104.

APA, 6th edition

A rum letter to a rum duke on a rum occasion [graphic]. (0 C.E.). [Caricatures and cartoons, Satires (Visual works) England 1762, Rebuses England 1762, Etchings England London 1762, Book illustrations]. E. Sumpter. https://collections.library.yale.edu/catalog/10713104.