Ibrahim Yahaya, Salissou, and Driss El Azzab. “Assessment of Recent GOCE-Based Global Geopotential Models and EGM2008 in Niger Republic”. Geodesy and Cartography 45, no. 3 (October 25, 2019): 116-125. Accessed November 25, 2024. https://gc.vgtu.lt/index.php/GAC/article/view/8699.