MLA

Williams, William Carlos, 1883-1963. The Audience Press. Box 1, folder 32. 1958. https://collections.library.yale.edu/catalog/17049447.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 1, folder 32"])(1958)[The Audience Press]. https://collections.library.yale.edu/catalog/17049447.