1. Baldwin, J. E., Harris, C. S., and Ryle, M.: 1973, Nature
241, 38.
2. Bender, P. L.: 1967, Phys. Rev. Letters
18, 562.
3. Coles, W. A., Rumsey, V. H., and Welch, W. J.: 1968, Astrophys. J. Letters
154, L61.
4. Cook, A. H.: 1966, Nature
211, 503.
5. Cowling, T. G.: 1957, Magnetohydrodynamics, Interscience Publishers, New York, p. 110.