Kheloufi, Noureddine, and Abdelhalim Niati. “Effect of Spatial Correlation on the Performances of Modernized GPS and Galileo in Relative Positioning”. Geodesy and Cartography 46, no. 2 (July 15, 2020): 89-97. Accessed February 28, 2021. https://journals.vgtu.lt/index.php/GAC/article/view/11009.