MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. [Modern art], typescript carbon and printed version. Box 47, folder 1385. 1927 Apr 4. https://collections.library.yale.edu/catalog/2042654.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 47, folder 1385"])(1927 Apr 4)[[Modern art], typescript carbon and printed version]. https://collections.library.yale.edu/catalog/2042654.