Ciuffo, L. E. del C., and M. Belli. “Radioactive Trace in Semi Natural Grassland. Effect of 40K in Soil and Potential Remediation”. Electronic Journal of Biotechnology, vol. 9, no. 3, June 2006, pp. 0-0, https://preprints.pucv.cl/index.php/ejbiotechnology/article/view/v9n3-5.