A Posteriori Error Estimators for Control Constrained Optimal Control Problems. - Kristina Kohls; Arnd Rösch; Kunibert G. Siebert (Constrained Optimization and Optimal Control for Partial Differential Equations, 2012)

A Posteriori Error Analysis of Optimal Control Problems with Control Constraints. - Kristina Kohls; Arnd Rösch; Kunibert G. Siebert (SIAM J. Control. Optim., 2014)