MLA

Martin, Jonathan, 1782-1838, artist. Her most gracious Majesty Adelaide, queen of Great Britain, &c &c consort of his present Majesty William the Fourth [art original].. [ca. 1830-1838]. https://collections.library.yale.edu/catalog/17339884.

APA, 6th edition

Martin, Jonathan, 1782-1838, artist. ([ca. 1830-1838])[Her most gracious Majesty Adelaide, queen of Great Britain, &c &c consort of his present Majesty William the Fourth [art original].]. https://collections.library.yale.edu/catalog/17339884.