1. Willis T. Pharmacentice rationalis sive diatriba medicamentorum operationibus in humano corpore. London: Hagoe-Comitis, 1674; 330.
2. Rake GW. A case of annular muscular hypertrophy of the esophagus. Guy’s Hosp Rep 1926;76:145–152.
3. Okinaka S, Nakao Y, Yoshikawa M. Digestive disease. Idiopathic dilatation of the esophagus. Autonomous nervous system and clinical medicine. Tokyo: Kyorin Shoin, 1964;117–122.
4. Castell DO, Herris LD. Hormonal control of gastroesophageal sphincter strength. N Engl J Med 1970;282:886–889.
5. Giles GR, Mason MC, Humphries C, et al. Action of gastrin on the lower esophageal sphincter in man. Gut 1969;10:730–734.