MLA

Fitzgerald, Robert, 1910-1985. Franklin, George. Box 12, folder 480. 1975-76. https://collections.library.yale.edu/catalog/17427389.

APA, 6th edition

Fitzgerald, Robert, 1910-1985. (["Box 12, folder 480"])(1975-76)[Franklin, George]. https://collections.library.yale.edu/catalog/17427389.