1. Higher-order ionospheric effects on the global positioning system observables and means of modeling them;Bassiri;Manuscr. Geo.,1993
2. The effect of the second order GPS ionospheric correction on receiver positions;Kedar;Geophys. Res. Lett.,2003
3. Observation model and parameter partials for the JPL VLBI parameter estimation software “MODEST”-1996;Sovers;JPL Publ.,1996
4. OCCAM Version 5.0 software: User guide;Titov