1. P. A. Redhead, Can. J. Phys. 42, 886 (1964).
2. D. Menzel and R. Gomer, J. Chem. Phys. 41, 3311 (1964).
3. V. N. Ageev and N. I. Ionov, Sov. Phys. Solid State 11, 2593 (1969).
4. V. N. Ageev, S. T. Dzhalilov, N. I. Ionov, and N. D. Potekhina, Sov. Phys. Tech. Phys. 21, 596 (1976).
5. V. N. Ageev, Yu. A. Kuznetsov, and B. V. Yakshinskii, Sov. Phys. Solid State 24, 199 (1982).