MLA

Pound, Ezra, 1885-1972. San Faustino, Jane. Box 46, folder 2016-2019. [1933?]-41. https://collections.library.yale.edu/catalog/17122625.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 46, folder 2016-2019"])([1933?]-41)[San Faustino, Jane]. https://collections.library.yale.edu/catalog/17122625.