Meena Marafi and  Mohan S. Rana,  Refining Waste Spent Hydroprocessing Catalyst and Their Metal Recovery.   journal   = {International Journal of Energy and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2017, vol. 130(10). 979 - 983
    [viewed 08 May 2024]. Available from: https://publications.waset.org/pdf/10008096.