MLA

Marsh, Othniel Charles, 1831-1899. Gruber, F.. Box 13, folder 551. 1872-1878. https://collections.library.yale.edu/catalog/32558537.

APA, 6th edition

Marsh, Othniel Charles, 1831-1899. (["Box 13, folder 551"])(1872-1878)[Gruber, F.]. https://collections.library.yale.edu/catalog/32558537.