MLA

Lord, James, 1922-2009. Wilder, Thornton. Box 20, folder 220. 1954 December. https://collections.library.yale.edu/catalog/2112206.

APA, 6th edition

Lord, James, 1922-2009. (["Box 20, folder 220"])(1954 December)[Wilder, Thornton]. https://collections.library.yale.edu/catalog/2112206.