MLA

Pound, Ezra, 1885-1972. Typescript. Box 68, folder 2975. n.d.. https://collections.library.yale.edu/catalog/17430538.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 68, folder 2975"])(n.d.)[Typescript]. https://collections.library.yale.edu/catalog/17430538.