1. N. G. Basov and A. N. Oraevskii, ?Negative temperatures obtained by heating and cooling of a system,? Zh. Eksp. Teor. Fiz.,44, No. 5 (1963).
2. J. D. Anderson and M. T. Madden, ?Population inversions behind normal shock waves,? AIAA J.,9, No. 8 (1971).
3. D. W. Gregg and S. J. Thomas, ?Analysis of the CS2-O2 chemical laser showing new lines and selective excitation,? J. Appl. Phys.,39, No. 9 (1968).
4. Yu. P. Grin', V. M. Polyakov, and V. G. Testov, ?Experimental investigation into the gas-dynamic amplification of laser radiation in N2O-N2-He mixture,? Pis'ma Zh. Eksp. Teor. Fiz.,18, No. 4 (1973).
5. A. G. Maki, ?Assignment of some DCN and HCN laser lines,? Appl. Phys. Lett.,12, No. 4, (1968).