MLA

Williams, William Carlos, 1883-1963. Partisan Review. Box 18, folder 563. 1941-1946. https://collections.library.yale.edu/catalog/17049526.

APA, 6th edition

Williams, William Carlos, 1883-1963. (["Box 18, folder 563"])(1941-1946)[Partisan Review]. https://collections.library.yale.edu/catalog/17049526.