MLA

Ely, William Davis, 1815-1908. Collins, David Chittenden. Box 1, folder 4. 1839. https://collections.library.yale.edu/catalog/32532130.

APA, 6th edition

Ely, William Davis, 1815-1908. (["Box 1, folder 4"])(1839)[Collins, David Chittenden]. https://collections.library.yale.edu/catalog/32532130.