Volume 15
MLA
Stein, Gertrude, 1874-1946. Volume 15. Box 90, folder 1701. ca. 1917-20. https://collections.library.yale.edu/catalog/2020774.
APA, 6th edition
Stein, Gertrude, 1874-1946. (["Box 90, folder 1701"])(ca. 1917-20)[Volume 15]. https://collections.library.yale.edu/catalog/2020774.