MLA

Stieglitz, Alfred, 1864-1946. Letters. Box 80, folder 1641-1650. 1945 Apr-Nov. https://collections.library.yale.edu/catalog/2046764.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 80, folder 1641-1650"])(1945 Apr-Nov)[Letters]. https://collections.library.yale.edu/catalog/2046764.