MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. Shawn, Ted. Box 74, folder 1943. circa 1930-1942, undated. https://collections.library.yale.edu/catalog/10076450.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 74, folder 1943"])(circa 1930-1942, undated)[Shawn, Ted]. https://collections.library.yale.edu/catalog/10076450.