Letters
MLA
Stieglitz, Alfred, 1864-1946. Letters. Box 62, folder 1428. 1921 Aug. https://collections.library.yale.edu/catalog/2039791.
APA, 6th edition
Stieglitz, Alfred, 1864-1946. (["Box 62, folder 1428"])(1921 Aug)[Letters]. https://collections.library.yale.edu/catalog/2039791.