MLA

Stieglitz, Alfred, 1864-1946. Sheeler, Charles R.. Box 45, folder 1064. 1911-22, n.d.. https://collections.library.yale.edu/catalog/17105655.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 45, folder 1064"])(1911-22, n.d.)[Sheeler, Charles R.]. https://collections.library.yale.edu/catalog/17105655.