Letter
MLA
Eliot, George, 1819-1880. Letter. Box 9. [1880] Dec 28. https://collections.library.yale.edu/catalog/10001424.
APA, 6th edition
Eliot, George, 1819-1880. (["Box 9"])([1880] Dec 28)[Letter]. https://collections.library.yale.edu/catalog/10001424.