MLA

Pound, Ezra, 1885-1972. Wilson, Robert McNair. Box 55, folder 2531-2537. 1934-59. https://collections.library.yale.edu/catalog/17122650.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 55, folder 2531-2537"])(1934-59)[Wilson, Robert McNair]. https://collections.library.yale.edu/catalog/17122650.