MLA

Butts, Mary, 1890-1937. "A Warrior Song," typescript carbon. Box 6, folder 112. n.d.. https://collections.library.yale.edu/catalog/16586552.

APA, 6th edition

Butts, Mary, 1890-1937. (["Box 6, folder 112"])(n.d.)["A Warrior Song," typescript carbon]. https://collections.library.yale.edu/catalog/16586552.