1. U. Kh. Kopvillem and V. R. Nagibarov, Fiz. Met. Metalloved. 15, 313 (1963).
2. N. A. Kurnit, I. D. Abella, and S. R. Hartmann, Phys. Rev. Lett. 6, 567 (1964).
3. É. A. Manykin and V. V. Samartsev, Optical Echo-Spectroscopy (Nauka, Moscow, 1984) [in Russian].
4. A. A. Kalachev and V. V. Samartsev, Coherent Phenomena in Optics (Kazan. Gos. Univ., Kazan, 2003) [in Russian].
5. S. A. Akhmanov, V. A. Vysloukh, and A. S. Chirkin, The Optics of Femtosecond Pulses (Nauka, Moscow, 1988) [in Russian].