[Aragón-Ángel A., Orús R., Hernández-Pajares M., Juan J.M., Sanz J. (2005) "Preliminary NeQuick assessment for future single frequency users of GALILEO", proceedings of the 6th Geomatic Week, Barcelona.]Search in Google Scholar
[Azpilicueta F., B. Nava, P. Coïsson and S.M. Radicella (2003) "Optimized NeQuick ionospheric model for point positioning", Proceedings of 2003 International Symposium on GPS/GNSS, Tokyo, Japan.]Search in Google Scholar
[CCIR (1967), Atlas of ionospheric characteristics, Comité Consultatif International des Radiocummnications, Report 340-4, International Telecommunication Union, Geneva.]Search in Google Scholar
[Coísson P.; S.M. Radicella; L. Ciraolo; B. Nava (2004)"Global performances of TEC models during high solar activity"., Navitec 2004 Proceedings.]Search in Google Scholar
[Di Giovanni, G. and S.R. Radicella (1990). An Analytical model of the electron density profile in the ionosphere. Advanced Space Research, 10, No. 11, 27-30.10.1016/0273-1177(90)90301-F]Search in Google Scholar
[Dodson, A.H. (1988). The Effects of Atmospheric Refraction on GPS Measurements. Seminar on the Global Positioning System, Nottingham university.]Search in Google Scholar
[IGS (2006). (2003-2004) IGS Annual Report, ( ftp://igscb.jpl.nasa.gov/igscb/resource/pubs/]Search in Google Scholar
[Klobuchar, J.A. (1982). Ionospheric Corrections for the Single Frequency User of the Global Positioning System. National Telesystems Conference, NTC'82. Systems for the Eighties. Galveston, Texas, USA (New York: IEEE, 1982).]Search in Google Scholar
[Klobuchar, J.A. (1987). Ionospheric Time-Delay Algorithm for Single-Frequency GPS Users. IEEE Transactions on Aerospace ad Electronic Systems. Vol. AES-23, No. 3, pp. 325-331.10.1109/TAES.1987.310829]Search in Google Scholar
[Komjathy, A. (1997). Global Ionospheric Total Electron Content Mapping Using The Global Positioning System. Ph.D. Thesis, New Brunswick University, Canada.]Search in Google Scholar
[Kunches, J.M. and Klobuchar, J.A. (2001). Eye on The Ionosphere: GPS after SA. GPS Solutions 4(3), PP. 52-54.10.1007/PL00012856]Search in Google Scholar
[Llewellyn, S.K. and Bent, R.B. (1973). Documentation and Description of the Bent Ionospheric Model. IAFCRL-TR-73-0657, July 1973, AD772733.10.21236/AD0772733]Search in Google Scholar
[Newby, S.P., Langely, R.B. and Janes, H.W. (1990). Ionospheric Modelling for Single Frequency Users of the Global Positioning System: A Status Report. In Proceeding of the 2nd International Symposium on Precise Positioning with GPS. Ottawa, Canada.]Search in Google Scholar
[Radicella, S.M., B. Nava, P. Coisson and R. Leitinger (2003). A Flexible 3D Ionospheric Model for Satellite Navigation Applications. 2003-International Symposium on GPS/GNSS, Japan, PP. 305-310.]Search in Google Scholar
[SIDC (2007). ( http://sidc.oma.be/sunspot-data/1998,1999,2001]Search in Google Scholar
[WDC (2007). World Data Center, Russia, ( http://www.wdcb.ru/stp/data/geomagni.ind/kp_ap/]Search in Google Scholar