MLA

Oh! You Are a Duck!!! [Art Original]. 0AD. https://collections.library.yale.edu/catalog/10970513.

APA, 6th edition

Oh! You are a duck!!! [art original]. (0 C.E.). [Humorous pictures, Puns (Visual works), Watercolors British 19th century, Ink drawings British 19th century]. https://collections.library.yale.edu/catalog/10970513.