1. Alpers DH: Functional gastrointestinal disorders. Hosp Pract ,April 1983, pp. 139–153.
2. Switz DM: What the gastroenterologist does all day: A survey of a state society’s practice. Gastroenterology 1976;70:1048–1050.
3. Mendeloff AL: Epidemiology of functional gastrointestinal disorders, in Chey WY (ed): Functional Disorders of the Gastrointestinal Tract. New York: Raven Press, 1983, pp. 13–19.
4. Chaudray NA, Truelove SC: The irritable colon syndrome. Q J Med 1962;31:307–322.
5. Thompson WG, Heaton KW: Functional bowel disorders in apparently healthy people. Gastroenterology 1980;79:283–288.