MLA

Stieglitz, Alfred, 1864-1946. Kennerley, Mitchell. Box 28, folder 652-654. 1911-41, n.d.. https://collections.library.yale.edu/catalog/17414988.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 28, folder 652-654"])(1911-41, n.d.)[Kennerley, Mitchell]. https://collections.library.yale.edu/catalog/17414988.