1. Eur. Pat. 572,782;Chem. Abstr., 1994,121, 255816.
2. H. El-Feky Said,Pharmazie, 1993,48, No. 12, 894.
3. V. K. Pandey,Curr. Sci., 1986,55, 243.
4. S. Kumar Atul Singh, A. K. Saxena, and K. Shanker,Ind. J. Chem. Sect. B, 1988,27, No. 5, 443.
5. J. G. Nair,J. Ind. Chem. Soc., 1965,42 B, No. 6, 359.