References
- British Patent 1,231,783 . 1968) to May . Baker Ltd.; B. Basil, E.J. Coffee, D.R. Maxwell, D. Sheffield and K.R.H. Wooldridge, J.Med.Chem., 13, 400 (1970)
- German Patents 2,237,228 . 1971 . 2,327,270 (1972) to Imperial Chemical Industries Ltd.
- Stephenson , O. 1954 . J. Chem. Soc. , : 1571