1. A new approach to the derivation of the total electron content using Doppler measurements from a single ground station;Lassudrie-Duchesne,1986
2. An Evaluation Method Combining the Differential Doppler Measurements from Two Stations that Enables the Calculation of the Electron Content of the Ionosphere;Leitinger;J. Geophys.,1975
3. Correction of ionospheric effects for the precise orbit determination of satellites;Foucher,1989
4. Documentation and description of the Bent ionospheric model;Llewellyn;AFCRL-TR-73-0657,1973