MLA

Stieglitz, Alfred, 1864-1946. Letters. Box 62, folder 1427. 1920 May-Jun. https://collections.library.yale.edu/catalog/2039790.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 62, folder 1427"])(1920 May-Jun)[Letters]. https://collections.library.yale.edu/catalog/2039790.