Prospective controlled study of endoscopic ultrasonography and endoscopic retrograde cholangiography in patients with suspected common-bileduct lithiasis. - Prat,F.; Amouyal,G.; Amouyal,P.; Pelletier,G.; Fritsch,J.; Choury,A.D.; Buffet,C.; Etienne,J.P. (Lancet, 1996)