MLA

Eliot, George, 1819-1880. Letter, Thursday morning, Mrs. Bray. Box 1. [1852 May 13]. https://collections.library.yale.edu/catalog/32366139.

APA, 6th edition

Eliot, George, 1819-1880. (["Box 1"])([1852 May 13])[Letter, Thursday morning, Mrs. Bray]. https://collections.library.yale.edu/catalog/32366139.