7Butters M. Hemorrhoids - etiology, symptoms and therapy[J]. Ther Umsch, 1997, 54(4) : 185.
8Spallanzani A, Ricchi E, Carriero A, et al. Rubber band ligation of hemorrhoids. Our experience [J]. Minerva Chir, 1997, 52(9) : 1047.
9Jensen DM, Machicado GA, Cheng S, et al. A randomized prospective study of endoscopic bipolar electrocoagulation and heater probe treatment of chronic rectal bleeding [J]. Gastrointest Endosc, 1997, 45(1) :20.
10Jensen DM, Jutabha R, Machicado GA, et al. Prospective randomized comparative study of bipolar electrocoagulation versus heater probe for treatment of bleeding internal hemorrhoids[J].Gastrointest Endosc, 1997, 46(5) : 435.