MLA

Boswell, James, 1740-1795. Bridgend. Box 153, folder 2806. 1757. https://collections.library.yale.edu/catalog/33557208.

APA, 6th edition

Boswell, James, 1740-1795. (["Box 153, folder 2806"])(1757)[Bridgend]. https://collections.library.yale.edu/catalog/33557208.