MLA

MacDonald, George, 1824-1905. Unidentified. Box 1, folder 38-39. 1856. https://collections.library.yale.edu/catalog/17297711.

APA, 6th edition

MacDonald, George, 1824-1905. (["Box 1, folder 38-39"])(1856)[Unidentified]. https://collections.library.yale.edu/catalog/17297711.