1. T. E. Madey (Surface Sci. 33 [1972] 355/76, 363/4).
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3. Ya. P. Zingerman, V. A. Ishchuk (Fiz. Tverd. Tela 8 [1966] 2999/3003; Soviet Phys.-Solid State 8 [1966] 2394/7).
4. V. S. Bosov, B. A. Chuikov (Ukr. Fiz. Zh. [Russ. Ed.] 18 [1973] 1571/2 nach C.A. 80 [1974] Nr. 19828).
5. R. G. Musket, J. Ferrante (J. Vacuum Sci. Technol. 7 [1970] 14/7).