MLA

Berthet, Louis, and printmaker. Williamm Pitt [Sic] Il Faut déclarer La Guerre à La France. [Graphic]. publisher not identified, 0AD. https://collections.library.yale.edu/catalog/10723153.

APA, 6th edition

Berthet, L., & printmaker. (0 C.E.). Williamm Pitt [sic] il faut déclarer la guerre à la France. [graphic] [Engravings France 1778, Stipple engravings France 1778, Portrait prints, Book illustrations]. publisher not identified. https://collections.library.yale.edu/catalog/10723153.