MLA

MacDonald, George, 1824-1905. Clemens, Samuel L.. Box 1, folder 57. 1873. https://collections.library.yale.edu/catalog/17297724.

APA, 6th edition

MacDonald, George, 1824-1905. (["Box 1, folder 57"])(1873)[Clemens, Samuel L.]. https://collections.library.yale.edu/catalog/17297724.