1. Steinberg, A. M., andStalford, H. L.,On Existence of Optimal Controls, Journal of Optimization Theory and Applications, Vol. 11, No. 3, 1973.
2. Berkovitz, L. D.,Lower Semicontinuity of Integral Functionals, Transactions of the American Mathematical Society, Vol. 192, No. 1, 1974.
3. Lee, E. B., andMarkus, M.,Foundations of Optimal Control Theory, John Wiley & Sons, New York, New York, 1967.
4. Dunford, N., andSchwartz, J. T.,Linear Operators, Part I, John Wiley & Sons (Interscience Publishers), New York, New York, 1959.
5. Gikhman, I. I., andSkorokhod, A. N.,Introduction to the Theory of Random Processes, W. B. Saunders, Philadelphia, Pennsylvania, 1969.