Ferrer Dufol, A., S. Nogué Xarau, F. Vargas Marcos, O. Castillo Soria, P. Gascó Alberich, A. de la Torre Reoyo, and E. de la Peña de Torres. “Health Environmental Risks Surveillance Systems: Toxicological Surveillance”. Spanish Journal of Environmental Health, vol. 4, no. 1-2, Dec. 2004, pp. 69-72, https://ojs.diffundit.com/index.php/rsa/article/view/353.