1. Akasofu, S.-I.: 1977,Physics of Magnetospheric Substorms, Reidel Pub. Co., Dordrecht, p. 137.
2. Alfvén, H.: 1957,Tellus,9, 92.
3. Alfvén, H. and Fälthammar, C.-G.: 1963,Cosmical Electrodynamics, Clarendon Press, Oxford, p. 120.
4. Alfvén, H.: 1976, in B. Hulquist and L. Stanflo (eds),Physics of the Hot Plasma in the Magnetosphere Plenum Press, New York.
5. Barnes, A.: 1966,Phys. Fluids,9, 1483.