MLA

Pound, Ezra, 1885-1972. Song [and Music]: typescript. Box 136, folder 5938. n.d.. https://collections.library.yale.edu/catalog/11689688.

APA, 6th edition

Pound, Ezra, 1885-1972. (["Box 136, folder 5938"])(n.d.)[Song [and Music]: typescript]. https://collections.library.yale.edu/catalog/11689688.