Buhles, Günter. “Amerikanische Individualisten: Komposition--von Charles Ives und Duke Ellington bis Thelonious Monk und John Cage.” Jazz Podium, Vol. 50, No. 1 (2001): 12-14.
Samuel, Claude. “Charles Ives: “Three-Page Sonata. The Anti-Abolitionist Riots. Study no. 20. Varied Air and Variations. Scene Episode. Piano Sonata no. 2.”” Diapason: le magazine du disque et de la musique vivante (2001): 92.