MLA

Pound, Ezra, 1885-1972. Laughlin, James. Box 28, folder 1199-1211. 1933-54. https://collections.library.yale.edu/catalog/17409018.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 28, folder 1199-1211"])(1933-54)[Laughlin, James]. https://collections.library.yale.edu/catalog/17409018.