MLA

Pound, Ezra, 1885-1972. Sonnets: typescript. Box 80, folder 3551. [1910]. https://collections.library.yale.edu/catalog/17430568.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 80, folder 3551"])([1910])[Sonnets: typescript]. https://collections.library.yale.edu/catalog/17430568.