MLA

Hawthorne, Nathaniel, 1804-1864. Choate, Rufus. Box 2, folder 42. [1855?] Oct 9. https://collections.library.yale.edu/catalog/2064557.

APA, 6th edition

Hawthorne, Nathaniel, 1804-1864. (["Box 2, folder 42"])([1855?] Oct 9)[Choate, Rufus]. https://collections.library.yale.edu/catalog/2064557.