Vestena, S., José Cambraia, M. A. Oliva, and J. A. Oliveira. 2007. “Cadmium Accumulation by Water Hyacinth and Salvinia Under Different Sulfur Concentrations”. Ecotoxicology and Environmental Contamination 2 (3):269-74. https://doi.org/10.5132/jbse.2007.03.010.