1. Schiffer, J.P., Kienle, P.: Z. Phys. A ? Atoms and Nuclei321, 181 (1985); Schiffer, J.P., Poulsen, O.: Europhys. Lett.1, 55 (1986)
2. Rahman, A., Schiffer, J.P.: Phys. Rev. Lett.57, 1133 (1986)
3. Habs, D., MPI report MPI H-1987-V10 (1987);
4. Hasse, R.: Private communication
5. Some of the present results have been reported at the Workshop & Symposium on the Physics of Low-Energy, Stored and Trapped Particles, June 14?18, 1987 in Stockholm, Sweden: Schiffer, J.P., Rahman, A.: Phys. Scr. (to be published); more general consideration of a confined one-component plasma will be reported elsewhere