Determining the amplitude of Mercury's long period librations with the BepiColombo radio science experiment⋆Giulia Schettino, Stefano Cicalò, Giacomo Tommei and Andrea MilaniEur. Phys. J. Plus, 132 5 (2017) 218DOI: https://doi.org/10.1140/epjp/i2017-11532-7