MLA

Nicholls, Norton, 1741?-1809. Charles de Bonstetten to Norton Nicholls. Bern. Concerns Thomas Gray; Bern, Switzerland. Box 1, folder 121. 1771 Sep 29. https://collections.library.yale.edu/catalog/17439918.

APA, 6th edition

Nicholls, Norton, 1741?-1809. (["Box 1, folder 121"])(1771 Sep 29)[Charles de Bonstetten to Norton Nicholls. Bern. Concerns Thomas Gray; Bern, Switzerland]. https://collections.library.yale.edu/catalog/17439918.