1. Repetitive behaviors;Blum,1999
2. Thumbsucking in an adult;Brody;JAMA,1964
3. Oral habits;Christensen,1988
4. Evaluation of swallowing disorders in children;Darrow;Otolaryngol Clin North Am,1998
5. Thumbsucking: Habit or symptom;Davidson;J Dent Child,1967