References
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- Friedman, H., “Physics of the upper atmosphere”, edited by J. A. Ratoliffe, 1960.
- Ogawa, Y., J. Geophys. Phys., 73 (1968), 6759.
- Subbaraya, B. H., Satya Prakash & Pareek, P. N., J. atmos. terr. Phys., 34 (1972), 1141.