MLA

Wilson, Edmund, 1895-1972. Arthur, Esther. Box 2, folder 57-60. 1922-59, n.d.. https://collections.library.yale.edu/catalog/2008064.

APA, 6th edition

Wilson, Edmund, 1895-1972. (["Box 2, folder 57-60"])(1922-59, n.d.)[Arthur, Esther]. https://collections.library.yale.edu/catalog/2008064.