MLA

Pound, Ezra, 1885-1972. Typescripts. Box 71, folder 3198. n.d.. https://collections.library.yale.edu/catalog/16055626.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 71, folder 3198"])(n.d.)[Typescripts]. https://collections.library.yale.edu/catalog/16055626.