1. Ansari, I. A., Fraser, B. J. 1985, Indian J. Radio and Space Phys., 14, 42.
2. Ansari, I. A., Fraser, B. J., McNabb, P. W. 1985, Indian J. Radio and Space Phys., 14, 1.
3. Bolshakova, O. V., Troitaskaya, V. A. 1968, Akad. Nauk. USSR., 180, 343.
4. Boller, B. R., Stolov, H. L. 1973, J. Geophys. Res., 78, 8078.
5. Chen, L., Hasegawa, A. 1974, J. Geophys. Res., 79, 1024.