[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
[Ezquer R.G., L.A. Scidá, Y. Migoya Orué, B. Nava, M.A. Cabrera, C. Brunini (2018). NeQuick 2 and IRI Plas VTEC predictions for low latitude and South American sector. Advances in Space Research, Volume 61, Issue 7, Pages 1803-1818.10.1016/j.asr.2017.10.003]Search in Google Scholar
[Hochegger, G., Nava, B., Radicella, S.M., Leitinger, R., (2000). A family of ionospheric models for different uses. Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science 25 (4), 307-310.10.1016/S1464-1917(00)00022-2]Search in Google Scholar
[ICTP (2017). The Abdus Salam International Centre for Theoretical Physics (ICTP) (http://tict4d.ictp.it/) Accessed (15/3/2017).]Search in Google Scholar
[IGS (2018a). (2003-2004) IGS Annual Report. (ftp://ftp.igs.org/pub/resource/pubs/2003-2004_IGS_Annual_Report.pdf) (Accessed 15/1/2018).]Search in Google Scholar
[IGS (2018b). IGS-GIMs (International GNSS Service-Global Ionospheric Maps (IONEX format)) (ftp://cddis.gsfc.nasa.gov/gps/products/ionex/) (Accessed 15/1/2018).]Search in Google Scholar
[ITU (2003). (International Telecommunication Union) Ionospheric propagation data and prediction methods required for the design of satellite services and systems. Recommendation P. 531-7, Geneva.]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
[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
[Nava B., P.Coı¨sson, S.M.Radicella (2008). A new version of the NeQuick ionosphere electron density model. Journal of Atmospheric and Solar-Terrestrial Physics 70 (2008) 1856-1862.10.1016/j.jastp.2008.01.015]Search in Google Scholar
[NOAA-NGDC (2017). National Centers for Environmental Informations.( https://www.ngdc.noaa.gov/) Accessed (1/4/2017).]Search in Google Scholar
[Okoh Daniel, Sylvester Onwuneme, Gopi Seemala, Shuanggen Jin, Babatunde Rabiu, Bruno Nava, Jean Uwamahoro (2018). Assessment of the NeQuick-2 and IRI-Plas 2017 models using global and long-term GNSS measurements. Journal of Atmospheric and Solar-Terrestrial Physics. Volume 170, May 2018, Pages 1-10.10.1016/j.jastp.2018.02.006]Search in Google Scholar
[Perna L., K. Venkatesh, V.G. Pillat, M. Pezzopane, P.R. Fagundes, R.G. Ezquer, M.A. Cabrera (2018). Bottom side profiles for two close stations at the southern crest of the EIA: Differences and comparison with IRI-2012 and NeQuick2 for low and high solar activity. Advances in Space Research 61 (2018) pages 295-315.10.1016/j.asr.2017.10.007]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
[Radicella, S.M., Leitinger, R., (2001). The evolution of the DGR approach to model electron density profiles. Advances in Space Research 27 (1), 35-40.10.1016/S0273-1177(00)00138-1]Search in Google Scholar
[Radicella, S.M., Zhang, M.L., (1995). The improved DGR analytical model of electron density height profile and total electron content in the ionosphere. Annali di Geofisica XXXVIII (1), 35-41.10.4401/ag-4130]Search in Google Scholar
[SIDC (2017). (http://sidc.oma.be/sunspot-data/1998,1999,2001). Accessed (1/4/2017).]Search in Google Scholar
[WDC (2017). World Data Center, Russia.]Search in Google Scholar
[(http://www.wdcb.ru/stp/data/geomagni.ind/kp_ap/) Accessed (1/4/2017).]Search in Google Scholar
