Cite

His Grace the Duke of Portland [graphic]

MLA

Murphy, John, approximately 1748-approximately 1820, printmaker. His Grace the Duke of Portland [graphic]. [31 March 1785]. https://collections.library.yale.edu/catalog/33191892.

APA, 6th edition

Murphy, John, approximately 1748-approximately 1820, printmaker. ([31 March 1785])[His Grace the Duke of Portland [graphic]]. https://collections.library.yale.edu/catalog/33191892.