1. A. V. Baev, "One formulation of the inverse boundary-value problem for the wave equation and an iterative solution method," Dokl. Akad. Nauk SSSR,287, No. 4, 818?821 (1986).
2. A. V. Baev, "An iterative solution method for one inverse problem for the wave equation on an interval," Zh. Vychisl. Mat. Mat. Fiz.,27, No. 7, 1022?1031 (1987).
3. A. V. Baev, "A solution method for the inverse scattering problem for the wave equation," Zh. Vychisl. Mat. Mat. Fiz.,28, No. 1, 25?33 (1988).
4. E. I. Gal'perin, Vertical Seismic Profiles [in Russian], Nedra, Moscow (1982).