Forones, N. M., Tanaka, M. and Falcão, J. B. (1997) “CEA as a prognostic index in colorectal cancer”, São Paulo Medical Journal, 115(6), pp. 1589–1592. Available at: https://periodicosapm.emnuvens.com.br/spmj/article/view/2172 (Accessed: 28 March 2025).