MLA

Stein, Gertrude, 1874-1946. Stein, Gertrude. Box 19, folder 318. ca. 1918-46. https://collections.library.yale.edu/catalog/2003465.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 19, folder 318"])(ca. 1918-46)[Stein, Gertrude]. https://collections.library.yale.edu/catalog/2003465.