MLA

Townshend, George Townshend, Marquis, 1724-1807. Bullock, Colby. Box 8. 1770 June 20. https://collections.library.yale.edu/catalog/31902985.

APA, 6th edition

Townshend, George Townshend, Marquis, 1724-1807. (["Box 8"])(1770 June 20)[Bullock, Colby]. https://collections.library.yale.edu/catalog/31902985.