1. Kaplansky, M.; Whitehead, M.A.:Can J Chem 45(1967),1669
2. Negita, H.; Satou, S.:Bull Chem Soc Jpn 29(1956),426
3. Negita, H.:J Sci Hiroshima Univ Ser A Math Phys Chem 21(1958),261
4. Whitehead, M.A.:Can J Chem 42(1964),1212
5. Kuz'min, A.I.; Chizhikova, S.M.; Denisova, G.M.; Zviadadze, G.N.; Dzevitskii, B.E.; Kuznetsov, S.I.:Zh Fiz Khim 53(1979),150