1. A. Bruce Langdon and Barbara F. Lasinski, Phys. Rev. Lett. 34, 834 (1975).PRLTAO0031-9007
2. P. Kaw, G. Schmidt, and T. Wilcox, Phys. Fluids 16, 1522 (1973).PFLDAS0031-9171
3. E. J. Valeo and K. G. Estabrook, Phys. Rev. Lett. 34, 1008 (1975).PRLTAO0031-9007
4. R. Allyn Saroyan, UCID 16550, 1974 (unpublished).
5. L. P. Boivin, Appl. Opt. 11, 1782 (1972).APOPAI0003-6935