MLA

Marsh, Othniel Charles, 1831-1899. Cohen, Joseph. Box 7, folder 267. 1887. https://collections.library.yale.edu/catalog/32555305.

APA, 6th edition

Marsh, Othniel Charles, 1831-1899. (["Box 7, folder 267"])(1887)[Cohen, Joseph]. https://collections.library.yale.edu/catalog/32555305.