MLA

Boswell, James, 1740-1795. Drumfork. Box 170, folder 2996. 1793, n.d.. https://collections.library.yale.edu/catalog/32498465.

APA, 6th edition

Boswell, James, 1740-1795. (["Box 170, folder 2996"])(1793, n.d.)[Drumfork]. https://collections.library.yale.edu/catalog/32498465.