@article{MOMA_1992__114_1_178589,
     author = {Nikolaos S. Papageorgiou},
     title = {Optimal {Control} and {Relaxation} of {Nonlinear} {Elliptic} {Systems.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {209--244},
     publisher = {mathdoc},
     volume = {114},
     number = {1},
     year = {1992},
     zbl = {0768.49003},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1992__114_1_178589/}
}