@article{COCV_2011__17_1_243_0,
     author = {Clason, Christian and Kunisch, Karl},
     title = {A duality-based approach to elliptic control problems in non-reflexive {Banach} spaces},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     pages = {243--266},
     publisher = {EDP-Sciences},
     volume = {17},
     number = {1},
     year = {2011},
     doi = {10.1051/cocv/2010003},
     mrnumber = {2775195},
     zbl = {1213.49041},
     language = {en},
     url = {http://archive.numdam.org/articles/10.1051/cocv/2010003/}
}