1. K. S. Jamwal, B. J. Ray-Ghatak, R. S. Thakur and P. R. Rao, in: Second Indo-Soviet Symposium on Natural Products including Pharmacology, abstr. pt II, 144. New Delhi 1970.
2. K. S. Jamwal, M. L. Sharma, N. Chandhoke and B. J. Ray Ghatak, Indian J. med. Sci.69, 763 (1972).
3. J. G. Cannon, J. med. Chem.17, 565 (1974).
4. S. N. Rastogi, J. S. Bindra and N. Anand, Indian J. Chem.9, 1175 (1971).
5. J. B. Taylor, J. W. Lewis and M. Jacklin, J. med. Chem.13, 1226 (1970).