Cite

[Portrait of Robert Walpole, 2nd Earl of Orford] [art original].

MLA

[Portrait of Robert Walpole, 2nd Earl of Orford] [Art Original]. 0AD. https://collections.library.yale.edu/catalog/33109731.

APA, 6th edition

[Portrait of Robert Walpole, 2nd Earl of Orford] [art original]. (0 C.E.). [Portrait paintings, Oil paintings (visual works)]. https://collections.library.yale.edu/catalog/33109731.