MLA

Van Dorn, Thomas J., 1817-1880. Diary: typescript copy. Box 1, folder 2. n.d.. https://collections.library.yale.edu/catalog/17443466.

APA, 6th edition

Van Dorn, Thomas J., 1817-1880. (["Box 1, folder 2"])(n.d.)[Diary: typescript copy]. https://collections.library.yale.edu/catalog/17443466.