Electron density distribution and solar plasma correction of radio signals using MGS, MEX, and VEX spacecraft navigation data and its application to planetary ephemeridesA. K. Verma, A. Fienga, J. Laskar, K. Issautier, H. Manche and M. GastineauA&A, 550 (2013) A124DOI: https://doi.org/10.1051/0004-6361/201219883