Ghobadi-Far, Khosro, Han, Shin-Chan, Sauber, Jeanne, Lemoine, Frank, Behzadpour, Saniya, Mayer-Guerr, Torsten, Sneeuw, Nico, Okal, Emile. Wiley-Blackwell; 2019. Gravitational changes of the Earth's free oscillation from earthquakes: Theory and feasibility study using GRACE inter-satellite tracking.