MLA

Stieglitz, Alfred, 1864-1946. Edward Stieglitz. Box 145, folder 2666. [1872], n.d.. https://collections.library.yale.edu/catalog/17357459.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 145, folder 2666"])([1872], n.d.)[Edward Stieglitz]. https://collections.library.yale.edu/catalog/17357459.