1. L. S. Pontryagin, V. G. Boltyanskii, R. V. Gamkrelidze, and E. F. Mishchenko, Mathematical Theory of Optimal Processes (Fizmatgiz, Moscow, 1961) [in Russian].
2. L. S. Pontryagin, The Maximum Principle (Fond Matem. Obrazovaniya i Prosveshcheniya, Moscow, 1998) [in Russian].
3. A. D. Ioffe and V. M. Tikhomirov, Theory of Extremal Problems (Nauka, Moscow, 1974) [in Russian].
4. V. M. Alekseev, V.M. Tikhomirov, and S. V. Fomin, Optimal Control (Nauka, Moscow, 1979) [in Russian].
5. F. P. Vasil’ev, Optimization Methods (Faktorial, Moscow, 2002) [in Russian].