Serovaiskii S. Ya.
          Approximate solution of optimization problems for infinite-dimensional 
          singular systems
        An optimal control problem is considered for a system described by 
          a singular equation of parabolic type. The study bases on a special 
          regularization method. We establish existence of a solution to the regularized 
          problem, as well as the corresponding necessary optimality conditions. 
          The results enable us to find an approximate solution to the original 
          problem even in the absence of solvability.