Jean-Pierre Dubois and  Jihad S. Daba and  M. Nader and  C. El Ferkh,  GSM Position Tracking using a Kalman Filter.   journal   = {International Journal of Electronics and Communication Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2012, vol. 68(8). 867 - 876
    [viewed 02 July 2020]. Available from: https://publications.waset.org/pdf/12100.