MLA

Bird, William, 1888-1963. Antheil and the Treatise on Harmony. Box 2, folder 59-63. [1922-24]. https://collections.library.yale.edu/catalog/16163083.

APA, 6th edition

Bird, William, 1888-1963. (["Box 2, folder 59-63"])([1922-24])[Antheil and the Treatise on Harmony]. https://collections.library.yale.edu/catalog/16163083.