MLA

Alderman W--d in the Character of Hercules Encountering the Hydra!. [Graphic]. Published by Benbow, 269 Strand, 0AD. https://collections.library.yale.edu/catalog/33245922.

APA, 6th edition

Alderman W--d in the character of Hercules encountering the Hydra!. [graphic]. (0 C.E.). [Caricatures and cartoons, Trials, litigation, etc, caricatures, Lithographs England London 19th century, Caricatures, Satires (Visual works) England 1820, Lithographs England London 1820, Annotations (Provenance) 19th century]. Published by Benbow, 269 Strand. https://collections.library.yale.edu/catalog/33245922.