1. J.A. Klobuchar & G.S. Hawkins,Effects of the ionosphere and space systems and communications, NRL. Washington DC, pp 421, 1975.
2. R.B. Bent, S.K. Llewellyn, G. Nesterczerk & R.E. Schimd,Effects of the ionosphere on space systems and communications, NRL, Washington DC, p 13, 1975.
3. R.E. Anderson,Effects of the ionosphere on space systems and communications, NRL, Washington DC, pp 411, 1975.
4. J.N. Bhar, S. Basu, A, Dasgupta, B.K. Guhatakurta & G.N. Bhattacharya,Scientific report on investigations on ionospheric electron content and electron density irregularities at low latitudes with geostationary satellites, Calcutta, 1976.
5. The calculation of the heights of the peaks of the ionospheric layers