MLA

Booth, W., and artist. Back of Gibraltar Hill [Art Original]. 0AD. https://collections.library.yale.edu/catalog/16193687.

APA, 6th edition

Booth, W., & artist. (0 C.E.). Back of Gibraltar Hill [art original] [Pictorial works, Views, Watercolors British 18th century]. https://collections.library.yale.edu/catalog/16193687.