Tierney WM, Adler DG, Conway JD, Diehl DL, Farraye FA, Kantsevoy SV, Kaul V, Kethu SR, Kwon RS, Mamula P, Pedrosa MC, Rodriguez SA. Overtube use in gastrointestinal endoscopy. Gastrointest Endosc. 2009 Nov; 70(5):828-34.