MLA

Williams, William Carlos, 1883-1963. Chicago Review Press. Box 4, folder 120. 1957-1958. https://collections.library.yale.edu/catalog/17049459.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 4, folder 120"])(1957-1958)[Chicago Review Press]. https://collections.library.yale.edu/catalog/17049459.