1. Saxena, G. M. and Seshadri, T. R.Proc. Ind. Acad. Sci., 1957,46 A, 218.
2. —————.. Ibid., 1958,47 A, 238.
3. Brahm Dev and Jain, B. D. Ibid., 1961,54 A, 341.
4. —————..Curr. Sci., 1961,30, 457.
5. Mittal, O. P. and Seshadri, T. R.J. Sci. Ind. Res., 1955,14 B, 76.