Randomised trial of endoscopic balloon dilation versus endoscopic sphincterotomy for removal of bileduct stones. - Bergmann,J.J.; Rauws,E.AJ.; Fockens,P.; van Berkel,A.M.; Bossuyt,P.M.; Tijssen,J.G.; Tytgat,G.N.; Huibregtse,K. (Lancet, 1997)