A Prospective, Randomized Multicenter Trial Comparing DoubleLayer and Polyethylene Stents for Malignant Distal Common Bile Duct Strictures - Tringali, A; Mutignani, M; Perri, V; Zuccalà, G; Cipolletta, L; Bianco, M A; Rotondano, G; Philipper, M; Schumacher, B; Neuhaus, H; Schmit, A; Devière, J; Costamagna, G (Endoscopy, 2003)