Letter
MLA
Stieglitz, Alfred, 1864-1946. Letter. Box 81, folder 1654. 1915 Aug 14. https://collections.library.yale.edu/catalog/2038422.
APA, 6th edition
Stieglitz, Alfred, 1864-1946. (["Box 81, folder 1654"])(1915 Aug 14)[Letter]. https://collections.library.yale.edu/catalog/2038422.