Hatem, Amaal J., Taghreed A. Naji, Ali A. Ne'ma, & Naz T. Jar Allah.
" Derivation of Mathematical Equations to Calculate the Geographical Coordinates of Unknown Position Situated at a Distance from the Observer Position Using GPS Data." <em>Ibn AL- Haitham Journal For Pure and Applied Science</em> [Online], 27.1 (2014): 154-160. Web. 30 Nov. 2019