N. Ullah and  A. Haddad and  F. Van Der Linde,  Effect of Integrity of the Earthing System on the Rise of Earth Potential.   journal   = {International Journal of Energy and Power Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2016, vol. 109(1). 62 - 68
    [viewed 18 April 2021]. Available from: https://publications.waset.org/pdf/10003460.