The sweet pea [graphic].
MLA
The Sweet Pea [Graphic]. Pubd August 20th 1812 by H Humphrey No 27 St James's Street, 0AD. https://collections.library.yale.edu/catalog/10967681.
APA, 6th edition
The sweet pea [graphic]. (0 C.E.). [Satires (Visual works) England 1812, Stipple engravings England London 1812, Etchings England London 1812]. Pubd August 20th 1812 by H Humphrey No 27 St James's Street. https://collections.library.yale.edu/catalog/10967681.