MLA

Butts, Mary, 1890-1937. Joyce, James. Box 1, folder 29. 1921 Nov 7, n.d.. https://collections.library.yale.edu/catalog/16893656.

APA, 6th edition

Butts, Mary, 1890-1937. (["Box 1, folder 29"])(1921 Nov 7, n.d.)[Joyce, James]. https://collections.library.yale.edu/catalog/16893656.