Jie-hui Tan, Wan-yan Zhou, Lei Zhou, Rong-chang Cao, and Guo-wei Zhang, “Viral hepatitis B and C infections increase the risks of intrahepatic and extrahepatic cholangiocarcinoma: Evidence from a systematic review and meta-analysis”, Turkish Journal of Gastroenterology, vol. 31, no. 3, pp. 246–256, Apr. 2020.