1. Agee, W.S., Turner, R.H., 1972. Optimal Estimation of Measurement bias. Technical Report no. 41. Mathematical Services Brunch, National Range Operations Dipectorate, White Sands Missile Range, New Maxico.
2. Quality of TEC estimated with ModIon using GPS and GLONASS data, Hindawi Publishing Corporation;Camargo;Math. Problems Eng.,2009
3. Variablility of GPS Satellite differential group delay biases;Coco;IEEE Trans. Aerospace Electron. Syst.,1991
4. Ganeshan, A.S., 2014. Indian Regional Navigation Satellite System. Signal in space ICD for standard positioning service, ISRO-IRNSS-ICD-SPS-1.0.
5. Derivation of TEC and estimation of instrumental biases from GEONET in Japan;Guanyi;Annales Geophysicae,2003