MLA

Stettheimer, Florine, 1871-1944. Diary. Box 7, folder 125-26. 1942 Dec, n.d.. https://collections.library.yale.edu/catalog/17054799.

APA, 6th edition

Stettheimer, Florine, 1871-1944. (["Box 7, folder 125-26"])(1942 Dec, n.d.)[Diary]. https://collections.library.yale.edu/catalog/17054799.