Beshr, Ashraf A. A., and Fawzi H. Zarzoura. “Approximation of Gravitational Calculation Based on Analytical Models”. Geodesy and Cartography 48, no. 3 (October 4, 2022): 124–133. Accessed November 22, 2024. https://btp.vgtu.lt/index.php/GAC/article/view/14854.