MLA

Zilboorg, James, 1892-1968. "M" general. Box 2, folder 42. 1912-1966. https://collections.library.yale.edu/catalog/17096135.

APA, 6th edition

Zilboorg, James, 1892-1968. (["Box 2, folder 42"])(1912-1966)["M" general]. https://collections.library.yale.edu/catalog/17096135.