MLA

Agar, John Samuel, approximately 1770-approximately 1835, printmaker. The Right Hon. William Wyndham Grenville, Lord Grenville from an original picture by W. Owen, Esq. R.A. / [graphic]. [1 March 1815]. https://collections.library.yale.edu/catalog/33191888.

APA, 6th edition

Agar, John Samuel, approximately 1770-approximately 1835, printmaker. ([1 March 1815])[The Right Hon. William Wyndham Grenville, Lord Grenville from an original picture by W. Owen, Esq. R.A. / [graphic]]. https://collections.library.yale.edu/catalog/33191888.