Tatyana Alexandrova and  Alexandr Alexandrov and  Nadezhda Nikolaeva,  Precious and Rare Metals in Overburden Carbonaceous Rocks: Methods of Extraction.   journal   = {International Journal of Materials and Metallurgical Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2015, vol. 107(11). 1307 - 1314
    [viewed 11 May 2024]. Available from: https://publications.waset.org/pdf/10002678.