1. H. Alfvén,Cosmical Electrodynamics(Clarendon Press, Oxford, 1950).
2. M. Kruskal, Princeton University, Project Matterhorn Report PM-S-33 (NYO-7903) (1958).
3. Equations of Motion for an Ideal Plasma.
4. The guiding center approximation to charged particle motion
5. More detailed derivations and more results of calculations are presented in Lawrence Radiation Laboratory Report UCRL 7246.