[1] V. S. Letokhov; IEEE J.. Quant. Electr., 1972, QE-8, 766～782.

[2] W. Η. Glenn; IEEE J. Quant. Electr., 1975, QE-11, 8～17.

[3] Μ. S. Demokan; INI J. Electronics, 1976, 41, No. 5, 421～470.

[4] D. J. Bradley; Proc. IEEE, 1974, 62, 313～345.

[6] D. Vonder binds; IEEE J r. Quant. Electr., 1972, QE-8,328～338.