WASET
    Satyendra Pratap Singh and  S. P. Singh,  Optimal Placement of Phasor Measurement Units Using Gravitational Search Method.   journal   = {International Journal of Energy and Power Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2015, vol. 99(3). 307 - 311
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/10000729.