1. [1] V.G. Boltyanskii, Sufficient conditions for optimality and the justification of the dynamic programming method, Izv. Akad. Nauk SSSR Ser. Mat. 28 (1964), No. 3, 481-514 (Russian).
2. [2] E.Choque Rivero, V.I. Korobov, and V.O. Skoryk, Controllability function as time of motion. I., Zh. Mat. Fiz. Anal. Geom. 11 (2004), No. 2, 208-225 (Russian).
3. [3] A.E. Choque Rivero, V.I. Korobov, and V.O. Skoryk, Controllability function as time of motion. II., Zh. Mat. Fiz. Anal. Geom. 11 (2004), No. 3, 341-354 (Russian).
4. [4] A.E. Choque Rivero, The controllability function method for the synthesis problem of a nonlinear control system, Int. Rev. Autom. Control 1 (2008), No. 4, 441-445.
5. [5] R. Conti, Return sets of a linear control process, J. Optim. Theory Appl. 41 (1983), No. 1, 37-53. CrossRef