Apel, P. H. (1958). The message of music. Vantage Press.
Lua i Stíl Chicago (17ú heag.)Apel, Paul Hermann. The Message of Music. New York: Vantage Press, 1958.
Lua MLA (9ú heag.)Apel, Paul Hermann. The Message of Music. Vantage Press, 1958.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.