MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. Baltimore Museum of Art. Box 4, folder 96. 1925. https://collections.library.yale.edu/catalog/17414350.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 4, folder 96"])(1925)[Baltimore Museum of Art]. https://collections.library.yale.edu/catalog/17414350.