Vennard, W. Singing: The mechanism and the technic.
Lua i Stíl Chicago (17ú heag.)Vennard, William. Singing: The Mechanism and the Technic. London, Oxford University Press, c1963.
Lua MLA (9ú heag.)Vennard, William. Singing: The Mechanism and the Technic.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.