MLA

Gregory, Alyse, 1882-1967. Wilkinson, Joan Lamburn. Box 41, folder 713-725. 1949-57, n.d.. https://collections.library.yale.edu/catalog/17072595.

APA, 6th edition

Gregory, Alyse, 1882-1967. (["Box 41, folder 713-725"])(1949-57, n.d.)[Wilkinson, Joan Lamburn]. https://collections.library.yale.edu/catalog/17072595.