MLA

Pound, Ezra, 1885-1972. Another Chance: typescript. Box 67, folder 2947. [1938 Sep]. https://collections.library.yale.edu/catalog/17122654.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 67, folder 2947"])([1938 Sep])[Another Chance: typescript]. https://collections.library.yale.edu/catalog/17122654.