1. Keith DA. Orofacial pain. In: Warfield CA, Bajwa ZH, editors. Principles and practice of pain medicine. 2nd ed, India, New Delhi, Tata McGraw Hill; 2005:1.p. 252.
2. Hainline B. Chronic pain: physiology, diagnostic, and management considerations. In: Waldman SD, editor. Pain management. Philadelphia: Saunders Elsevier; 2007. p. 212.