Endoscopic treatment combined with extracorporeal shock wave lithotripsy of difficult bile duct stones. - Mora,J.; Aguilera,V.; Sala,T.; Martinez,F.; Bastida,G.; Palau,A.; Arguello,I.; Pons,V.; Pertejo,V.; Berenguer,J.; Alapont,J.M. (Gastroenterol Hepatol, 2002)