THE ULTRASONOGRAFIC ASSESMENT OF THE LEVELS AND CAUSES IN BILIARY OBSTRUCTION - CANER, M. Emin; HİLMİOĞLU, Fatih and BOYACIOĞLU, Sedat and Doğru, A. İhsan and TAŞ, İsmet and; ÇİN, Gülay and ŞAHİN, Burhan (Turkish Journal of Gastroenterology, 1992)