1. V. S. Averbakh, S. N. Vlasov, and V. I. Talanov, Izv. Vyssh. Uchebn. Zaved., Radiofiz. 10, 1333 (1967).
2. J. W. Campbell, Instrum. Control Syst. 40 (11), 75 (1967).
3. S. V. Sikora and G. S. Simkin, in Proceedings of the Kharkov State Research Institute of Metrology (Moscow, 1969), p. 104 [in Russian].
4. V. I. Perel’ and I. V. Rogova, Opt. Spektrosk. 25, 716 (1968).
5. P. J. Brannon, Appl. Opt. 15, 1119 (1976).