O. Sezgin, E. Altıntaş, F. Ateş, S. Yaraş, B. Sarıtaş, and K. Aydın, “Air cholangiogram is not sufficent to detect common bile duct stones during ERCP”, Turkish Journal of Gastroenterology, vol. 25, no. 1, pp. 319–320, Jan. 2014.