Essam Mohamed Al-Karargy, and Gomaa Mohamed Dawod. “Optimum Combinations of GGM and GDEM Models for Precise National Geoid Modelling”. Proceedings of Engineering and Technology Innovation 18 (February 3, 2021): 15–24. Accessed April 20, 2024. https://ojs.imeti.org/index.php/PETI/article/view/6452.