MLA

Stieglitz, Alfred, 1864-1946. Emmeline O. Stieglitz. Box 130, folder 2523. ca. 1910. https://collections.library.yale.edu/catalog/2002562.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 130, folder 2523"])(ca. 1910)[Emmeline O. Stieglitz]. https://collections.library.yale.edu/catalog/2002562.