Barham, T. J., & Nelson, D. L. (1991). The boy's changing voice: New solutions for today's choral teacher. Belwin Mills.
Lua i Stíl Chicago (17ú heag.)Barham, Terry Joe, agus Darolyne L. Nelson. The Boy's Changing Voice: New Solutions for Today's Choral Teacher. Miami, Fl.: Belwin Mills, 1991.
Lua MLA (9ú heag.)Barham, Terry Joe, agus Darolyne L. Nelson. The Boy's Changing Voice: New Solutions for Today's Choral Teacher. Belwin Mills, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.