WASET
    Sergio Perez Rodriguez,  Numerical Modeling of Artisanal and Small-Scale Mining of Coltan in the African Great Lakes Region.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2023, vol. 203(11). 147 - 150
    [viewed 28 April 2024]. Available from: https://publications.waset.org/pdf/10013331.