1. Utility of serum CA19-9 in diagnosis of cholangiocarcinoma: In comparison with CEA
   Xing-Lei Qin et al, 2004, World Journal of Gastroenterology CrossRef
2. Identification of osteopontin as the most consistently over-expressed gene in intrahepatic cholangiocarcinoma: Detection by oligonucleotide microarray and real-time PCR analysis
   Holger G Hass et al, 2008, World Journal of Gastroenterology CrossRef