MLA

Nicholls, Norton, 1741?-1809. Thomas Gray to Jane Floyer Nicholls. Cambridge. Concerns William Johnson Temple. Box 1, folder 51. 1766 Aug 26. https://collections.library.yale.edu/catalog/17439848.

APA, 6th edition

Nicholls, Norton, 1741?-1809. (["Box 1, folder 51"])(1766 Aug 26)[Thomas Gray to Jane Floyer Nicholls. Cambridge. Concerns William Johnson Temple]. https://collections.library.yale.edu/catalog/17439848.