MLA

Marsh, Othniel Charles, 1831-1899. Gundlack, George. Box 13, folder 557. 1875. https://collections.library.yale.edu/catalog/32558627.

APA, 6th edition

Marsh, Othniel Charles, 1831-1899. (["Box 13, folder 557"])(1875)[Gundlack, George]. https://collections.library.yale.edu/catalog/32558627.