1. E. Galitzenstein, C.C. Wolf: J. Chem. Soc. Ind.,69, 289 (1950).
2. P.B.D. de la Mare, R. Bolton: Electrophilic Addition to Unsaturated Systems, p. 73. Elsevier, Amsterdam/London/New York 1966.
3. Y.H. Chua, J.S. Ratcliffe: Mech. Chem. Eng. Trans. I. E. Aust.,7, 6 (1971).
4. P. Shykes: A guidebook to Mechanism in Organic Chemistry. (3rd Ed.), p. 156. Longman, London 1970.
5. G. Heublein: Z. Chem.,9, 281 (1969).