MLA

Fitzgerald, Robert, 1910-1985. Young, Kathleen Tankersley. Box 40, folder 1632. 1931 Nov 4. https://collections.library.yale.edu/catalog/17427392.

APA, 6th edition

Fitzgerald, Robert, 1910-1985. (["Box 40, folder 1632"])(1931 Nov 4)[Young, Kathleen Tankersley]. https://collections.library.yale.edu/catalog/17427392.