1. L.A. Pakhomycheva, E.A. Sviridenkov, A.F. Suchkov, L.V. Titova, S.S. Churilov: ZhETP Pisma Red. 12, 60 (1970) [JETP Lett. 12, 43 (1970)]
2. T.W. Hänsch, A.L. Schawlow, P.E. Toschek: J. QE-8, 802 (1972)
3. V.M. Baev, T.P. Belikova, E.A. Sviridenkov, A.F. Suchkov: Zh. Eksp. Teor. Fiz. 74, 43 (1978) [Sov. Phys. JETP 74, 21 (1978)]
4. A.A. Kachanov, T.V. Plakhotnik: Opt. Commun. 47, 257 (1983)
5. V.M. Baev, E.A. Sviridenkov, A.F. Suchkov, D.D. Toptygin: Kvantovaja Electron. 7, 1112 (1980) [Sov. J. Quantum Electron. 10, 638 (1980)]