1. Examination of the esophago-gastric junction area and fundus by retroflexion of the flexible-tip gastroscope: an analysis of 100 consecutive attempts;Burke;Gastrointest Endosc,1970
2. The gastroscopic retroflexion method in the diagnosis of sliding esophageal hiatus hernia;Schachter;Gastrointest Endosc,1970
3. Fifteen years later: colonoscopic retroflexion revisited;Cutler;Am J Gastroenterol,1999
4. Colonoscopic retroflexion in the evaluation of rectal disease;Grobe;Am J Gastroenterol,1982