1. Lang IM, Dantas RO, Cook IJ, et al.: Videoradiographic, manometric and electromyographic assessment of upper esophageal sphincter. Am J Physiol 1991, 260:G911-G919.
2. Asoh R, Goyal RK: Manometry and electromyography of the upper esophageal sphincter in the opossum. Gastroenterology 1978, 74:514–520.
3. Cook IJ, Dodds WJ, Dantas RO, et al.: Opening mechanisms of the upper esophageal sphincter. Am J Physiol 1989, 257:G748-G759.
4. Gerhardt D, Hewett J, Moeschberger M, et al.: Human upper esophageal sphincter pressure profile. Am J Physiol 1980, 239:G49-G52.
5. Kahrilas PJ, Dodds WJ, Dent J, et al.: Upper esophageal sphincter function during deglutition. Gastroenterology 1988, 95:52–62.