MLA

Sketches Taken at Print Sales [Graphic]. Published Feby. the 1st, 1798, by Sylvester Harding, 127 Pall Mall, 0AD. https://collections.library.yale.edu/catalog/33231140.

APA, 6th edition

Sketches taken at print sales [graphic]. (0 C.E.). [Portraits, Portrait, portraits, Etchings, Group portraits, Portrait prints, Etchings England London 1798, Stipple engravings England London 1798]. Published Feby. the 1st, 1798, by Sylvester Harding, 127 Pall Mall. https://collections.library.yale.edu/catalog/33231140.