Nicholls, David Roy. “New and Experimental Compositional Tech- niques in American Music from Charles Ives to the Second World War.” Ph.D. diss., University of Cambridge, 1986.
Belland, Anna. “Piano Variations by Ives, Valen, Lutoslawski, Dallapiccola- A Discussion of Their Styles and Forms.” D. Mus. dissertation, Indiana University, 1981.