MLA

Matthias, Blanche (1887-1983). Monroe, Harriet. Box 2, folder 72. 1932 Oct 1. https://collections.library.yale.edu/catalog/17170700.

APA, 6th edition

Matthias, Blanche (1887-1983). (["Box 2, folder 72"])(1932 Oct 1)[Monroe, Harriet]. https://collections.library.yale.edu/catalog/17170700.