MLA

Pound, Ezra, 1885-1972. American Imperialist: "Old Habits or New": typescript. Box 126, folder 5226. [1943] Feb 2. https://collections.library.yale.edu/catalog/17122836.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 126, folder 5226"])([1943] Feb 2)[American Imperialist: "Old Habits or New": typescript]. https://collections.library.yale.edu/catalog/17122836.