1. Uniqueness of the stationary point for the one-dimensional inverse problem in two-dimensional space
2. A. S. Alekseev and S. I. Kabanikhin, Inverse problems and new technologies in geophysics. In: Proc. of Intern. conf. Mathematical Methods in Geophysics. Institute of Comp. Math. and Geoph., Novosibirsk, 2003 (in Russian)