MLA

Nicholls, Norton, 1741?-1809. Charles Floyer to Jane Floyer Nicholls. Fort George, India. Concerns Indian affairs; Norton Nicholls. Box 1, folder 13. 1757 Jun 25. https://collections.library.yale.edu/catalog/17439810.

APA, 6th edition

Nicholls, Norton, 1741?-1809. (["Box 1, folder 13"])(1757 Jun 25)[Charles Floyer to Jane Floyer Nicholls. Fort George, India. Concerns Indian affairs; Norton Nicholls]. https://collections.library.yale.edu/catalog/17439810.