MLA

Eliot, George, 1819-1880. Letter, Sunday, to Mr. Bray. Box 1. [1848 Jun 11]. https://collections.library.yale.edu/catalog/32366095.

APA, 6th edition

Eliot, George, 1819-1880. (["Box 1"])([1848 Jun 11])[Letter, Sunday, to Mr. Bray]. https://collections.library.yale.edu/catalog/32366095.