1. Professional Voice: The Science and Art of Clinical Care;Sataloff,1991
2. Grounds in Speech Therapy: Treating Voice Disorders;Pinho,2003
3. Evaluation and Treatment of Voice Disorders;Behlau,1995
4. Vocal warming techniques used by theater teachers;Aydos;Rev CEFAC,2004
5. Singing-Diction;Perelló,1975