MLA

Harding, G. P. (George Perfect), 1780-1853, artist. Catherine eldest daughter of Sir Robert Walpole [art original]. [between 1802 and 1853?]. https://collections.library.yale.edu/catalog/11138689.

APA, 6th edition

Harding, G. P. (George Perfect), 1780-1853, artist. ([between 1802 and 1853?])[Catherine eldest daughter of Sir Robert Walpole [art original]]. https://collections.library.yale.edu/catalog/11138689.