1. Exner, O., Chem. Listy, 1973, vol. 67, no. 2, p. 135.
2. Pal’m, V.A., Osnovy kolichestvennoi teorii organicheskikh reaktsii (Principles of the Quantitative Theory of Organic Reactions), Moscow: Khimiya, 1977, p. 260.
3. Leffler, J.E. and Grunwald, E., Rates and Equilibria of Organic Reactions, New York: Wiley, 1963, p. 101.
4. Isaacs, N.S., Physical Organic Chemistry, New York: Wiley, 1992, p. 102.
5. McBane, G.C., J. Chem. Educ., 1998, vol. 75, no. 3, p. 919.