Cite

Vox populi in private ; Vox populi in publick [graphic].

MLA

Vox Populi in Private ; Vox Populi in Publick [Graphic]. Sold by W. Humphrey, 227 Strand, 0AD. https://collections.library.yale.edu/catalog/10723030.

APA, 6th edition

Vox populi in private ; Vox populi in publick [graphic]. (0 C.E.). [Satires (Visual works) England 1783, Etchings England London 1783]. Sold by W. Humphrey, 227 Strand. https://collections.library.yale.edu/catalog/10723030.