References
Cummings CW, Flint PW, Haughey BH, et al. Otolaryngology: Head & Neck Surgery. 4th ed. St Louis, Mo: Mosby; 2005:3226.
Rakel P. Conn’s Current Therapy 2005. 57th ed. Philadelphia, Pa: WB Saunders; 2005:226-227.
Goldman L, Ausiello D. Cecil Textbook of Medicine. 22nd ed. Philadelphia, Pa: WB Saunders; 2004:240-241.