Juliana A. Galhardi and  Daniel M. Bonotto,  Geochemistry of Natural Radionuclides Associated with Acid Mine Drainage (AMD) in a Coal Mining Area in Southern Brazil.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2015, vol. 101(5). 521 - 528
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/10001339.