MLA

Jones, David, 1895-1974. David Jones letters to Harman Grisewood. Box 1, folder 21. 1956. https://collections.library.yale.edu/catalog/32259108.

APA, 6th edition

Jones, David, 1895-1974. (["Box 1, folder 21"])(1956)[David Jones letters to Harman Grisewood]. https://collections.library.yale.edu/catalog/32259108.