1. Adams D.R. and Lenhart S.: An Obstacle Control Problem with a Source Term, to appear in Applied Mathematics and Optimization.
2. Adams D.R. and Lenhart S., Optimal Control of the Obstacle for a Parabolic Variational Inequality, to appear in Journal of Mathematical Analysis and Applications.
3. Adams D.R., Lenhart S. and Yong J., Optimal Control of the Obstacle for an Elliptic Variational Inequality, Applied Mathematics and Optimization, 38, 1998 121?140.
4. Barbu V., Analysis and Control of Non Linear Infinite Dimensional Systems, Mathematics in Science and Engineering, 190, Academic Press, New York 1993.
5. Bergounioux M., Optimal Control of Semilinear Elliptic Obstacle Problem, Journal of Nonlinear and Convex Analysis, 3, (2002).