MLA

Eliot, George, 1819-1880. Letter. Box 11. 1885 Jan 14. https://collections.library.yale.edu/catalog/10001573.

APA, 6th edition

Eliot, George, 1819-1880. (["Box 11"])(1885 Jan 14)[Letter]. https://collections.library.yale.edu/catalog/10001573.