MLA

Carter, John, 1748-1817, artist. The armour worn by Francis I of France [art original] : drawn from the original at Strawberry-Hill. [approximately 1790]. https://collections.library.yale.edu/catalog/16729694.

APA, 6th edition

Carter, John, 1748-1817, artist. ([approximately 1790])[The armour worn by Francis I of France [art original] : drawn from the original at Strawberry-Hill]. https://collections.library.yale.edu/catalog/16729694.