“The Determination of Heavy Metals (Cd and Pb) in Bivalve Molluscs Commercial Interest Four Estuaries of the Gulf of Guayaquil”. Revista Científica Ciencias Naturales Y Ambientales, vol. 4, no. 1, Dec. 2010, p. 14, https://doi.org/10.53591/cna.v4i1.277.