MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. [Modern art], typescript carbon. Box 47, folder 1386. 1927 May 12. https://collections.library.yale.edu/catalog/32209792.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 47, folder 1386"])(1927 May 12)[[Modern art], typescript carbon]. https://collections.library.yale.edu/catalog/32209792.