1. Eckardt AJ, Eckardt VF. Treatment and surveillance strategies in achalasia: an update. Nat Rev Gastroenterol Hepatol. 2011;8(6):311–9.
2. Vaezi MF, Pandolfino JE, Vela MF. ACG clinical guideline: diagnosis and management of achalasia. Am J Gastroenterol. 2013;108(8):1238–50.
3. Sonnenberg A. Hospitalization for achalasia in the United States 1997–2006. Dig Dis Sci. 2009;54(8):1680–5.
4. Gennaro N, Portale G, Gallo C, Rocchietto S, Caruso V, Costantini M, et al. Esophageal achalasia in the Veneto region: epidemiology and treatment. Epidemiology and treatment of achalasia. J Gastrointest Surg. 2011;15(3):423–8.
5. Boeckxstaens GE, Zaninotto G, Richter JE. Achalasia. Lancet. 2014;383(9911):83–93.