1. Carlson, D. A., Haurie, A., andLeizarowitz, A.,Infinite-Horizon Optimal Control: Deterministic and Stochastic Systems, 2nd Edition, Springer-Verlag, New York, New York, 1991.
2. McShane, E. J.,Relaxed Control and Variational Problems, SIAM Journal on Control, Vol. 5, pp. 438?485, 1967.
3. Cesari, L.,Optimization-Theory and Applications, Springer-Verlag, New York, New York, 1983.
4. Lewis, T. R., andSchmalensee, R.,Optimal Use of Renewable Resources with Nonconvexities in Production, Essays in the Economics of Renewable Resources, Edited by L.J. Morman and D.F. Spulber, North-Holland Publishing Company, Amsterdam, Holland, pp. 95?111, 1982.
5. Gamkrelidze, R. V.,On Some Extremal Problems in the Theory of Differential Equations with Applications to the Theory of Optimal Control, SIAM Journal on Control, Vol. 3, pp. 106?128, 1965.