MLA

Sub Poena. Pub'd May 11, 1787 by S.W. Fores, No. 3 Piccadilly, 0AD. https://collections.library.yale.edu/catalog/10728313.

APA, 6th edition

Sub poena. (0 C.E.). [Caricatures and cartoons, Satires (Visual works) England 1787, Etchings England London 1787]. Pub'd May 11, 1787 by S.W. Fores, No. 3 Piccadilly. https://collections.library.yale.edu/catalog/10728313.