A. E. Emam and  M. Abd Elghany,  Collocation Assessment between GEO and GSO Satellites.   journal   = {International Journal of Aerospace and Mechanical Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2015, vol. 108(12). 2124 - 2132
    [viewed 23 April 2021]. Available from: https://publications.waset.org/pdf/10003166.