MLA

Stieglitz, Alfred, 1864-1946. Hartley, Marsden. Box 23, folder 536-541. 1924-42. https://collections.library.yale.edu/catalog/17105632.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 23, folder 536-541"])(1924-42)[Hartley, Marsden]. https://collections.library.yale.edu/catalog/17105632.