Sheppard, B. (2008). The everything singing book: From mastering breathing techniques to performing live - all you need to hit the right notes. Adams Media Corp.
Chicago-Zitierstil (17. Ausg.)Sheppard, Bettina. The Everything Singing Book: From Mastering Breathing Techniques to Performing Live - All You Need to Hit the Right Notes. Avon, MA: Adams Media Corp, 2008.
MLA-Zitierstil (9. Ausg.)Sheppard, Bettina. The Everything Singing Book: From Mastering Breathing Techniques to Performing Live - All You Need to Hit the Right Notes. Adams Media Corp, 2008.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.