1. Two anomalies in the ionosphere;Appleton;Nature,1946
2. Bilitza, D., 2002. Ionospheric models for radio propagation studies. In: Stone, W.R. (Ed.), Review of Radio Sciences. IEEE and Wiley, pp. 625–679.
3. Evaluation of GPS ionospheric time-delay model;Feess;IEEE Trans. Aerosp. Electron. Syst.,1987
4. Klobuchar-like local model of quiet space weather GPS ionospheric delay for northern Adriatic;Filjar;J. Navig.,2009
5. Han, L., Zhang, H., Huang, Y., Zhu, W., Ping, J., 2006. Improving Klobuchar type ionospheric delay model using 2D GPS TEC over China. In: 36th COSPAR Scientific Assembly, p. 2718.