MLA

Kent, Charles, 1823-1902. Commission of William Kent. Box 6, folder 230. 1783 May 17. https://collections.library.yale.edu/catalog/10257460.

APA, 6th edition

Kent, Charles, 1823-1902. (["Box 6, folder 230"])(1783 May 17)[Commission of William Kent]. https://collections.library.yale.edu/catalog/10257460.