MLA

Rudge, Olga, 1895-1996. Concerto in La: Manuscript in the hand of Ezra Pound, with incomplete pages in another hand. Box 159, folder 3723. n.d.. https://collections.library.yale.edu/catalog/2007453.

APA, 6th edition

Rudge, Olga, 1895-1996. (["Box 159, folder 3723"])(n.d.)[Concerto in La: Manuscript in the hand of Ezra Pound, with incomplete pages in another hand]. https://collections.library.yale.edu/catalog/2007453.