1. V.S. Letokhov: Science 180, 451 (1973)
2. C.B. Moore: Acc. Chem. Res. 323 (1973)
3. R.F. Gross: Opt. Eng. 13, 506 (1974)
4. V.S. Letokhov, C.B. Moore: Kvantovaya Elektron. 3, 248, 485 (1976) [in Russian]; Sov. J. Quantum Electron, 6, 129, 259 (1976)
5. S.R. Leone: In Physics in Quantum Electronics, Vol.4, Laser Photochemistry, Tunable Lasers and Other Topics, ed. by S.F. Jacobs, M. Sargent III, M.O. Scully, C.T. Walker (Addison-Wesley, Reading 1976) p.17; J.P. Aldrige, J.H. Birely, C.D. Cantrell, D.C. Cartwright: ibid., p.57