1. Pontryagin, S.L., Boltyanskii, V.G., Gamkrelidze, R.V., and Mishchenko, E.F., Matematicheskaya teoriya optimal’nykh protsessov (Mathematical Theory of Optimal Processes), Moscow: Nauka, 1969.
2. Lauden, D.F., Optimal Trajectories for Space Navigation, London, 1963. Translated under the title Optimal’nye traektorii dlya kosmicheskoi navigatsii, Moscow: Mir, 1966.
3. Rockafellar, R.T., Convex Analysis, Princeton: Princeton Univ., 1970. Translated under the title Vypuklyi analiz, Moscow: Mir, 1973.