1. R. H. Dicke, Phys. Rev. 93, 99 (1954).
2. É. A. Manykin and V. V. Samartsev, Optical Echo Spectroscopy (Nauka, Moscow, 1984).
3. Yu. V. Naboĭkin, V. V. Samartsev, P. V. Zinov’ev, and N. B. Silaeva, Coherent Spectroscopy of Molecular Crystals (Naukova Dumka, Kiev, 1986).
4. L. I. Men’shikov, Usp. Fiz. Nauk 169, 113 (1999).
5. M. Gross and S. Haroche, Phys. Rep. 93, 301 (1982).