1. B.E. Knox: InTrace Analysis by Mass Spectrometry, ed. by A.J. Ahearn (Academic Press, New York, London 1972)
2. V.S. Letokhov: Kvantovaya Electron.2, 930 (1975)
3. F.J. Vastola, A.J. Pirone: InAdvances in Mass Spectrometry, Vol. 4 (Heyden, London 1968), p. 107
4. R.O. Mumma, F.J. Vastola: Org. Mass. Spectrom.6, 1373 (1972)
5. R.D. Macfarlane, D.F. Torgerson: Science191, 920 (1976)