MLA

Butts, Mary, 1890-1937. Colville-Hyde, Mary. Box 1, folder 6-7. [1928-32]. https://collections.library.yale.edu/catalog/16893634.

APA, 6th edition

Butts, Mary, 1890-1937. (["Box 1, folder 6-7"])([1928-32])[Colville-Hyde, Mary]. https://collections.library.yale.edu/catalog/16893634.