1. Pontryagin, L.S., Boltyanskii, V.G., Gamkrelidze, R.V., Mishchenko, E.F.: The Mathematical Theory of Optimal Processes. Interscience, New York (1962)
2. Chertovskih, R., Karamzin, D., Khalil, N.T., Pereira, F.L.: An indirect method for regular state-constrained optimal control problems in flow fields. IEEE Trans. Autom. Control (2019, submitted)
3. Joseph, A.: Measuring Ocean Currents: Tools, Technologies, and Data. Elsevier Science, Amsterdam (2013)
4. Gamkrelidze, R.V.: Optimal control processes with restricted phase coordinates. Izv. Akad. Nauk SSSR Scr. Mat. 24, 315–356 (1960)
5. Berkovitz, L.D.: On control problems with bounded state variables. J. Math. Anal. Appl. 5, 488–498 (1962)