SKEIVALAS, Jonas. Covariation of ionospheric influence in the GPS observations. Geodesy and Cartography, [S. l.], v. 32, n. 1, p. 3–5, 2012. DOI: 10.3846/13921541.2006.9636681. Disponível em: https://journals.vilniustech.lt/index.php/GAC/article/view/10955. Acesso em: 1 jun. 2025.