MLA

Mary Princess of Orange, Countess of Nassow &Cc [Art Original]. 0AD. https://collections.library.yale.edu/catalog/16704422.

APA, 6th edition

Mary Princess of Orange, Countess of Nassow &cc [art original]. (0 C.E.). [Portrait drawings, Ink drawings British 18th century, Wash drawings British 18th century]. https://collections.library.yale.edu/catalog/16704422.