MLA

Stieglitz, Alfred, 1864-1946. Anderson, Sherwood. Box 2, folder 35-45. 1922-38, n.d.. https://collections.library.yale.edu/catalog/17105611.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 2, folder 35-45"])(1922-38, n.d.)[Anderson, Sherwood]. https://collections.library.yale.edu/catalog/17105611.