MLA

Williams, William Carlos, 1883-1963. McKenzie. Box 14, folder 439. 1930. https://collections.library.yale.edu/catalog/17049510.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 14, folder 439"])(1930)[McKenzie]. https://collections.library.yale.edu/catalog/17049510.