MLA

Pound, Ezra, 1885-1972. Pearson, Norman Holmes. Box 14, folder 344. 1961-70. https://collections.library.yale.edu/catalog/10167561.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 14, folder 344"])(1961-70)[Pearson, Norman Holmes]. https://collections.library.yale.edu/catalog/10167561.