Ortiz-Zamora, G, MA Huerta-Díaz, DA Salas-de-León, and MA Monreal-Gómez. 2002. “Degrees of Pyritization in the Gulf of Mexico in Sediments Influenced by the Coatzacoalcos and the Grijava-Usumacinta Rivers”. Ciencias Marinas 28 (4):369-79. https://doi.org/10.7773/cm.v28i4.238.