MLA

Stieglitz, Alfred, 1864-1946. [On why he does not give permission to have his photographs reproduced] (for America As Americans See It), holograph. Box 98, folder 1927. 1931 Nov 11. https://collections.library.yale.edu/catalog/10933035.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 98, folder 1927"])(1931 Nov 11)[[On why he does not give permission to have his photographs reproduced] (for America As Americans See It), holograph]. https://collections.library.yale.edu/catalog/10933035.