MLA

Boswell, James, 1740-1795. Sasine. Box 82, folder 1572. 1518. https://collections.library.yale.edu/catalog/16227556.

APA, 6th edition

Boswell, James, 1740-1795. (["Box 82, folder 1572"])(1518)[Sasine]. https://collections.library.yale.edu/catalog/16227556.