MLA

Sawyer, Richard, 1785-1852, printmaker. Villiers, Duke of Buckingham assassinated by John Felton at Portsmouth, Augt. 23d. 1628 [graphic]. [July 1822]. https://collections.library.yale.edu/catalog/33328910.

APA, 6th edition

Sawyer, Richard, 1785-1852, printmaker. ([July 1822])[Villiers, Duke of Buckingham assassinated by John Felton at Portsmouth, Augt. 23d. 1628 [graphic]]. https://collections.library.yale.edu/catalog/33328910.