MLA

Butts, Mary, 1890-1937. Butts, Anthony. Box 1, folder 4. [ca. 1923-36]. https://collections.library.yale.edu/catalog/16893632.

APA, 6th edition

Butts, Mary, 1890-1937. (["Box 1, folder 4"])([ca. 1923-36])[Butts, Anthony]. https://collections.library.yale.edu/catalog/16893632.