A novel method of forceps biopsy improves the diagnosis of proximal biliary malignancies - Kulaksiz, Hasan; Strnad, Pavel; Römpp, Achim; von Figura, Guido; Barth, Thomas; Esposito, Irene; Schirmacher, Peter; Henne-Bruns, Doris; Adler, Guido; Stiehl, Adolf (Digestive diseases and sciences, 2011)