1. Anzer, U.: 1968,Solar Phys. 3, 298.
2. Artsimovich, L. A.: 1964,Controlled Thermonuclear Reactions, Gordon and Breach, New York, p. 250
3. Beckers, J. M.: 1974, private communication.
4. Beckers, J. M. and Schröter, E. H.: 1969a,Solar Phys. 4, 192, 303.
5. Beckers, J. M. and Schröter, E. H.: 1969b,Solar Phys. 7, 22.