1. R.I. Personov, E.I. Al'shits, L.A. Bykovskaya: Opt. Commun6, 169 (1972)
2. R.I. Personov: InMolecular Spectroscopy, a series in Modern Problems in Solid State Physics, ed. by V.M. Agranovich and R.M. Hochstrasser (North-Holland, Amsterdam 1981)
3. L.A. Rebane: Zh. Prikl. Spektrosk.34, 1023 (1981)
4. A.A. Gorokhovskii, R.K. Kaarli, L.A. Rebane: JETP Lett.20, 216 (1974); Opt. Commun.16 282 (1976)
5. S. Voelker, J.H. van der Waals: Mol. Phys.32, 1703 (1976)