MLA

Roberts, Piercy, active 1791-1805, printmaker. Behold the strangest groupe under heaven, of oddities we just make seven [graphic]. [approximately 1795]. https://collections.library.yale.edu/catalog/10939203.

APA, 6th edition

Roberts, Piercy, active 1791-1805, printmaker. ([approximately 1795])[Behold the strangest groupe under heaven, of oddities we just make seven [graphic]]. https://collections.library.yale.edu/catalog/10939203.