1. a) P. R. Wells, “Linear Free Energy Relationships,” Academic Press, New York, N.Y., 1968;
2. b) J. E. Leffler and E. Grunwald, “Rates and Equilibria of Organic Reactions,” Wiley, New York, N.Y., 1963;
3. c) M. Charton, CHEMTECH, 502 (Aug 1974); 245 (April 1975);
4. d) C. D. Ritchie and W. F. Sage, Prog, Phys. Org. Chem., 2, 323 (1964).
5. a) C. D. Johnson, “The Hammett Equation,” Cambridge University Press, London, 1973;