MLA

Marsh, Othniel Charles, 1831-1899. Rockwell, George. Box 28, folder 1172. 1874. https://collections.library.yale.edu/catalog/32566301.

APA, 6th edition

Marsh, Othniel Charles, 1831-1899. (["Box 28, folder 1172"])(1874)[Rockwell, George]. https://collections.library.yale.edu/catalog/32566301.