2Gockel I,Müller M,Schumacher J.Achalasia--a disease of unknown cause that is often diagnosed too late[J].Dtsch Arz-tebl Int.2012,109(12):209-14.
3Akyüz F,Ibri im D,Balik E,et al.Evaluation of malignancy risk and endoscopic follow up in achalasia:Case report[J].Turk J Gastroenterol.2006,17(1):46-9.
4Zendehdel K,Nyrén O,Edberg A,Ye W.Risk of esophageal ad-enocarcinoma in achalasia patients,a retrospective cohort study in Sweden[J].Am J Gastroenterol.2011,106(1):57-61.
5Gockel I, Muller M, Schumacher J. Achalasia--a disease of unknown cause that is often diagnosed too late[J]. Dtsch Arztebl Int, 2012, 109(12):209-214. DOI:10. 3238/arztebl. 2012. 0209.
