1. I. Singh, “What would happen if GPS failed?,” awesomeness, 10 September 2018.
2. Z. Siejka, “Multi-GNSS As A Combination Of GPS, Glonass And Beidou Measurements Carried Out In Real Time,” artificial satellites, vol. 50, no. 4-2015, pp. 217-229, 2015.
3. P. F. Faria, Positioning with Combined GPS and GLONASS Observations, Av. Rovisco Pais: Técnico Lisboa, 2013
4. M. Osama, “Different Techniques for Detecting and Repairing GPS Cycle Slip,” in master Thesis, Cairo, 2015.
5. W. Hofmann, L. H and C. J, “Global Positioning System- theory and practice,” in 5th edition, New York, USA, 2001.