MLA

[Two Soldiers Fighting] [Graphic]. Publish'd Octr.1, 1791 by W. Birch, Hampstead Heath from a drawing by Hogarth, 0AD. https://collections.library.yale.edu/catalog/16194028.

APA, 6th edition

[Two soldiers fighting] [graphic]. (0 C.E.). [Annotations (Provenance) 18th century, Etchings England London 1791]. Publish'd Octr.1, 1791 by W. Birch, Hampstead Heath from a drawing by Hogarth. https://collections.library.yale.edu/catalog/16194028.