1. J. P. Aubin and I. Ekeland, Applied Nonlinear Analysis (Wiley, New York, 1984; Mir, Moscow, 1988).
2. F. P. Vasil’ev, E. V. Khoroshilova, and A. S. Antipin, Moscow Univ. Comput. Math. Cybernet. 34(3), 113 (2010).
3. A. N. Tikhonov and V. Ya. Arsenin, Methods for Solving Ill-Posed Problems (Nauka, Moscow, 1979) [in Russian].
4. A. B. Bakushinskii and A. V. Goncharskii, Iterative Methods for Solving Ill-Posed Problems (Nauka, Moscow, 1989) [in Russian].
5. F. P. Vasil’ev, Optimization Methods (Faktorial, Moscow, 2002) [in Russian].