MLA

Stieglitz, Alfred, 1864-1946. White, Stanford. Box 52, folder 1251. 1903 Jan 14. https://collections.library.yale.edu/catalog/17105665.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 52, folder 1251"])(1903 Jan 14)[White, Stanford]. https://collections.library.yale.edu/catalog/17105665.