MLA

Stieglitz, Alfred, 1864-1946. Delaney, Beauford. Box 188, folder 3171. 1950-73. https://collections.library.yale.edu/catalog/32189123.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 188, folder 3171"])(1950-73)[Delaney, Beauford]. https://collections.library.yale.edu/catalog/32189123.