MLA

Oliver Crom[Well]s s[Peech] [to] the [Ass] & [Fox] 1756 [Graphic]. Publish'd according to act Sept. 24, 1756, by Darly & Edwards at the Acorn facing Hungerford, Strand, 0AD. https://collections.library.yale.edu/catalog/10714629.

APA, 6th edition

Oliver Crom[well]s s[peech] [to] the [ass] & [fox] 1756 [graphic]. (0 C.E.). [Caricatures and cartoons, Satires (Visual works) England 1756, Etchings England London 1756, Rebuses, Book illustrations]. Publish'd according to act Sept. 24, 1756, by Darly & Edwards at the Acorn facing Hungerford, Strand. https://collections.library.yale.edu/catalog/10714629.