MLA

Sully, Alfred, 1821-1879. Miscellaneous. Box 5, folder 79. n.d.. https://collections.library.yale.edu/catalog/16703609.

APA, 6th edition

Sully, Alfred, 1821-1879. (["Box 5, folder 79"])(n.d.)[Miscellaneous]. https://collections.library.yale.edu/catalog/16703609.