MLA

Kay, John, 1742-1826, printmaker. Mr. Obrien the Irish giant the tallest man in the known world being near nine feet high [graphic]. [1803]. https://collections.library.yale.edu/catalog/17339360.

APA, 6th edition

Kay, John, 1742-1826, printmaker. ([1803])[Mr. Obrien the Irish giant the tallest man in the known world being near nine feet high [graphic]]. https://collections.library.yale.edu/catalog/17339360.