MLA

Stieglitz, Alfred, 1864-1946. "Overture, Manfred - Schumann," watercolor on paper board. Box 159, folder 2914. 1907. https://collections.library.yale.edu/catalog/2002426.

APA, 6th edition

Stieglitz, Alfred, 1864-1946. (["Box 159, folder 2914"])(1907)["Overture, Manfred - Schumann," watercolor on paper board]. https://collections.library.yale.edu/catalog/2002426.