Promise Sethembiso Ngema and  Freeman Ntuli and  Mohamed Belaid,  The removal of Ni, Cu and Fe from a Mixed Metal System using Sodium Hypophosphite as a Reducing Agent.   journal   = {International Journal of Materials and Metallurgical Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2012, vol. 68(8). 864 - 867
    [viewed 25 October 2021]. Available from: https://publications.waset.org/pdf/5356.