Cite

Humphry Duke of Gloucester, uncle to the King and Protector Henry VI : from an original picture in the collection of the Hon. Horace Walpole, Strawbery [sic] Hill / [graphic]

MLA

Gardiner, W. N. (William Nelson), 1766-1814, printmaker. Humphry Duke of Gloucester, uncle to the King and Protector Henry VI : from an original picture in the collection of the Hon. Horace Walpole, Strawbery [sic] Hill / [graphic]. [1 December 1790]. https://collections.library.yale.edu/catalog/16229193.

APA, 6th edition

Gardiner, W. N. (William Nelson), 1766-1814, printmaker. ([1 December 1790])[Humphry Duke of Gloucester, uncle to the King and Protector Henry VI : from an original picture in the collection of the Hon. Horace Walpole, Strawbery [sic] Hill / [graphic]]. https://collections.library.yale.edu/catalog/16229193.