1. Adam, J. C., Laval, G., and Pesme, D.: 1980, J. Physique Suppl. 41, C3?383.
2. Al'tshul', L. M., and Karpman, V. I.: 1966, Soviet Phys. JETP 22, 361.
3. Ashour-Abdalla, M.: 1972, Planetary Space Sci. 20, 639.
4. Assco, E., Laval, G., Pellat, R., Welti, R., and Roux, A.: 1971, J. Plasma Phys. 8, 341.
5. Benson, R. F. and Calvert, W.: 1980, Geophys. Res. Letters 6, 479.