MLA

Queen Caroline Britain's Best Hope!! England's Sheet-Anchor!!!. [Graphic]. Published October 19th, 1820, by John Fairburn, Broadway, Ludgate Hill, 0AD. https://collections.library.yale.edu/catalog/16817025.

APA, 6th edition

Queen Caroline Britain's best hope!! England's sheet-anchor!!!. [graphic]. (0 C.E.). [Caricatures and cartoons, Satires (Visual works) England 1820, Etchings England London 1820, Watermarks (Paper) J. Whatman 1819]. Published October 19th, 1820, by John Fairburn, Broadway, Ludgate Hill. https://collections.library.yale.edu/catalog/16817025.