MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. Stransky, Josef. Box 92, folder 2354. 1921 Mar 19. https://collections.library.yale.edu/catalog/32209811.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 92, folder 2354"])(1921 Mar 19)[Stransky, Josef]. https://collections.library.yale.edu/catalog/32209811.