1. In the words of a colleague theoretician in quite a different field: F Forstmann, private communication (1984).
2. D. B. Graves and K. F. Jensen, Proc. MRS Spring Meeting (1986) on Plasma Processing, Palo Alto, USA.
3. H. F. Winters, Materials Science and Engineering 70, 53 (1985).
4. J. A. Thornton, Thin Solid Films 107, 3 (1983).
5. Proceedings of the NATO-ASI on “Non-Equilibrium Processes in Partially Ionized Gases”, Italy (1989), edited by J.N. Bardsley and A. Capitelli.