On the Existence of Optimal Random Controls H. BeckerV. Mandrekar Indiana University Mathematics Journal 1969 text pdf 10.1512/iumj.1969.18.18083 10.1512/iumj.1969.18.18083 en Indiana Univ. Math. J. 18 (1969) 1151 - 1166 state-of-the-art mathematics http://iumj.org/access/