R. M. A. M. Moura, D. Matos, M. M. Galvão Filho, G. D’Ippólito, J. Sjzenfeld, and L. M. Giuliano, “Value of CEA level determination in gallbladder bile in the diagnosis of liver metastases secondary to colorectal adenocarcinoma”, Sao Paulo Med J, vol. 119, no. 3, pp. 110–113, May 2001.