MLA

Pound, Ezra, 1885-1972. Maverick, Lewis. Box 2, folder 43. 1957-59. https://collections.library.yale.edu/catalog/17078449.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 2, folder 43"])(1957-59)[Maverick, Lewis]. https://collections.library.yale.edu/catalog/17078449.