MLA

Sergeant, Elizabeth Shepley, 1881-1965. Family history and reminiscences. Box 18, folder 394-95. n.d.. https://collections.library.yale.edu/catalog/10544205.

APA, 6th edition

Sergeant, Elizabeth Shepley, 1881-1965. (["Box 18, folder 394-95"])(n.d.)[Family history and reminiscences]. https://collections.library.yale.edu/catalog/10544205.