ALBERSHEIM, Gerhard. Die Tonstufe. Die Musikforschung, [S. l.], v. 16, n. 2, p. 139–152, 1963. DOI: 10.52412/mf.1963.H2.2375. Disponível em: https://mf.publia.org/mf/article/view/2375. Acesso em: 26 juli. 2026.