Are serum and biliary carcinoembryonic antigen and carbohydrate antigen19-9 determinations reliable for differentiation between benign and malignant biliary disease? - AKDOĞAN, Meral; PARLAK, Erkan; KAYHAN, Burçak; BALK, Mevhibe; ERSAVAŞTF, Gül; ŞAHİN, Burhan (Turkish Journal of Gastroenterology, 2003)