MLA

Stein, Gertrude, 1874-1946. Darantière, Maurice. Box 136, folder 3115. 1946 Aug 17. https://collections.library.yale.edu/catalog/10634502.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 136, folder 3115"])(1946 Aug 17)[Darantière, Maurice]. https://collections.library.yale.edu/catalog/10634502.