MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. Ray, Man. Box 30, folder 868. 1920-51, n.d.. https://collections.library.yale.edu/catalog/2040523.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 30, folder 868"])(1920-51, n.d.)[Ray, Man]. https://collections.library.yale.edu/catalog/2040523.