MLA

Pound, Ezra, 1885-1972. Durrell, Lawrence. Box 14, folder 642. [1933]. https://collections.library.yale.edu/catalog/17122553.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 14, folder 642"])([1933])[Durrell, Lawrence]. https://collections.library.yale.edu/catalog/17122553.