MLA

Ioanna Lady Bergavenny from an Original Picture at Strawberry Hill. [Graphic]. Publish'd May 12, 1798, by S. Harding, 127 Pall Mall, & P. Brown, Crown St., Soho, 0AD. https://collections.library.yale.edu/catalog/16229208.

APA, 6th edition

Ioanna Lady Bergavenny from an original picture at Strawberry Hill. [graphic]. (0 C.E.). [Portrait prints, Stipple engravings England London 1798]. Publish'd May 12, 1798, by S. Harding, 127 Pall Mall, & P. Brown, Crown St., Soho. https://collections.library.yale.edu/catalog/16229208.