%0 Journal Article %A Bergounioux, Maïtine %A Mignot, Fulbert %T Optimal control of obstacle problems : existence of Lagrange multipliers %J ESAIM: Control, Optimisation and Calculus of Variations %D 2000 %P 45-70 %V 5 %I EDP-Sciences %U http://www.numdam.org/item/COCV_2000__5__45_0/ %G en %F COCV_2000__5__45_0