MLA

Sergeant, Elizabeth Shepley, 1881-1965. Correspondence about. Box 17, folder 372. 1927-42, n.d.. https://collections.library.yale.edu/catalog/10542971.

APA, 6th edition

Sergeant, Elizabeth Shepley, 1881-1965. (["Box 17, folder 372"])(1927-42, n.d.)[Correspondence about]. https://collections.library.yale.edu/catalog/10542971.