MLA

Williams, William Carlos, 1883-1963. The Colorado Review. Box 4, folder 129. 1956-1957. https://collections.library.yale.edu/catalog/17049460.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 4, folder 129"])(1956-1957)[The Colorado Review]. https://collections.library.yale.edu/catalog/17049460.