Schwertberger, G. (1979). Happy Piano: Pop Sound Introduction. Doblinger.
Lua i Stíl Chicago (17ú heag.)Schwertberger, Gerald. Happy Piano: Pop Sound Introduction. Wien: Doblinger, 1979.
Lua MLA (8ú heag.)Schwertberger, Gerald. Happy Piano: Pop Sound Introduction. Doblinger, 1979.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.