MLA

Stein, Gertrude, 1874-1946. Hartley, Marsden. Box 110, folder 2223-2224. 1912-34. https://collections.library.yale.edu/catalog/2017534.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 110, folder 2223-2224"])(1912-34)[Hartley, Marsden]. https://collections.library.yale.edu/catalog/2017534.