1. M. Born, Z. Physik, 1 (1920) 45
2. L. Onsager, Phys. Rev., 54 (1938) 554
3. I. Adamczewski, Ionization, Conductivity and Breakdown in Dielectric Liquids, Taylor and Fracis, London, 1969
4. G.R. Freeman, J. Chem. Phys., 38 (1963) 1022; 39 (1963) 988
5. A.O. Allen and A. Hummel, Disc. Farad. Soc., 36 (1963) 95