MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. Miro, Joan. Box 108, folder 2627. 1925-49, n.d.. https://collections.library.yale.edu/catalog/11594335.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 108, folder 2627"])(1925-49, n.d.)[Miro, Joan]. https://collections.library.yale.edu/catalog/11594335.