MLA

Marsh, Othniel Charles, 1831-1899. McAdams, William. Box 22, folder 871. 1888-1890. https://collections.library.yale.edu/catalog/32563144.

APA, 6th edition

Marsh, Othniel Charles, 1831-1899. (["Box 22, folder 871"])(1888-1890)[McAdams, William]. https://collections.library.yale.edu/catalog/32563144.