MLA

Pound, Ezra, 1885-1972. Eden. Box 97, folder 4133. n.d.. https://collections.library.yale.edu/catalog/17122734.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 97, folder 4133"])(n.d.)[Eden]. https://collections.library.yale.edu/catalog/17122734.