1. Cauffman, D. P. and Gurnett, D. A.: 1972, Space Sci. Rev.
13, 369.
2. DeForest, S. E.: 1972, J. Geophys. Res.
77, 651.
3. Fahleson, U.: 1967, Space Sci. Rev.
7, 238.
4. Grard, R. J. L.: 1972, Internal Working Paper No. 663, ESTEC, Noordwijk, Netherlands.
5. Heppner, J. P.: 1972, in Proc. of the Symposium on Critical Problems of Magnetospheric Physics, Madrid, Spain, p. 107.