1[1]Muller AD,Sonnenberg A.Prevention of colorectal cancer by flexible endoscope and polypectomy:a case-control study of 32702 veterans[J].Ann Intern Med,1995,123:904-910.
2[2]Van Gossum A,Cozzoli A,Adler M,et al.Colonoscopic snare polypectomy:analysis of 1485 resections comparing two types of current[J].Gastrointest Endosc,1992,38:472-475.
