MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. Clippings regarding announcement, exhibitions, and catalog. Box 93, folder 2373. 1941-50, n.d.. https://collections.library.yale.edu/catalog/2014458.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 93, folder 2373"])(1941-50, n.d.)[Clippings regarding announcement, exhibitions, and catalog]. https://collections.library.yale.edu/catalog/2014458.