1. Danilin, A.N., Ostafiichuk, R.M., and Sakharov Ya.A., Sb. nauchn. trudov pyatoi rossiskou konferentsii po atmosfernomu elektrichestvu (Proc. 5th Russ. Conf. on Atmospheric Electricity), Vladimir: Vladimir State Univer., 2003, p. 262.
2. Danilin, A.N., Ostafiichuk, R.M., Sakharov Ya.A., et al., Trudy 8 mezhdunarodnogo sinposiuma po elektromagnitnoi sovmestimosti i elektromagnitnoi ekologii (Proc. 8th Int. Symp. on Electromagnetic Compatibility and Electromagnetic Ecology), St. Petersburg, 2009, p. 237.
3. Lehtinen, M. and Pirjola, R., Ann. Geophys., 1985, vol. 3,no. 4, p. 479.
4. Viljanen, A.T., Pirjola, R.J., Pajunpaa, K.M., and Pulkkinen, A., Proc. 8th Int. Symp. on Electromagetic Compatibility and Electromagnetic Ecology, St. Petersburg, 2009, p. 227.
5. Elovaara, J., Lindblad, P., Viljanen, A., et al., Proc. CIGRE General Session, Paris, 1992, p. 10.