MLA

Hulme, Kathryn, 1900-1981. Griffin, John Howard. Box 17, folder 438. 1956. https://collections.library.yale.edu/catalog/32297957.

APA, 6th edition

Hulme, Kathryn, 1900-1981. (["Box 17, folder 438"])(1956)[Griffin, John Howard]. https://collections.library.yale.edu/catalog/32297957.