WASET
    L. Bartonová and  D. Juchelková and  Z. Klika and  B. Cech,  On Unburned Carbon in Coal Ash from Various Combustion Units.   journal   = {International Journal of Materials and Metallurgical Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2011, vol. 52(4). 294 - 297
    [viewed 18 April 2024]. Available from: https://publications.waset.org/pdf/4929.