Welch, G. F. (1983). Improvability of poor pitch singing: Experiments in feedback. University of London.
Lua i Stíl Chicago (17ú heag.)Welch, Graham F. Improvability of Poor Pitch Singing: Experiments in Feedback. University of London, 1983.
Lua MLA (8ú heag.)Welch, Graham F. Improvability of Poor Pitch Singing: Experiments in Feedback. University of London, 1983.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.