MLA

Stieglitz, Alfred, 1864-1946. Cramer, Konrad. Box 10, folder 264. 1913-20?, 1936. https://collections.library.yale.edu/catalog/17105622.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 10, folder 264"])(1913-20?, 1936)[Cramer, Konrad]. https://collections.library.yale.edu/catalog/17105622.