1. Athay R. G. 1976, inThe Solar Chromosphere and Corona: Quite Sun, D. Reidel, Dordrecht. p. 123.
2. Bessey, R. J., Liebenberg, D. H. 1984,Solar Phys.,94, 239.
3. Bhatnagar, A., Jadhav, D. B., Jain, R. M., Shelke, R. N., Purohit, S. P. 1982,Proc. Indian Nat. Sci.Acad., A48, Suppl. 3, 29.
4. Chandrasekhar, T., Desai, J. N., Angreji, P. D. 1981,Appl. Opt.,20, 2172.
5. Deone, A. B. 1974,PhD Thesis, Moscow Univ.