1. V. A. Vershkov and S. V. Mirnov, “The Role of Impurities in he Present Tokamak Experiments,” PPPL Matt-Trans 113, 1973; Nucl. Fusion 14 (1974) 383.
2. G. G. Kelley, “Modification of the Belt Limiter Concept to Provide for Purging of Impurities,” ORMAK II/TTF Design Memo No. 17, Nov. 22, 1974.
3. W. Bieger, K. H. Dippel, G. Fuchs, and G. Wolf, presented at the Symposium on Plasma-Wall Interaction, Jülich, 1976.
4. J. F. Schivell, “Method of Plasma Impurity Control Without Magnetic Divertor,” PPPL-1342, June 1977.
5. R. W. Conn, I. N. Sviatoslavsky, and D. K. Sze, in Proc. 8th Symposium on Engineering Problems in Fusion Research, San Francisco, 1979.