@article{COCV_2007__13_2_331_0,
     author = {Bertone, Simone and Cellina, Arrigo},
     title = {On the existence of variations, possibly with pointwise gradient constraints},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     pages = {331--342},
     publisher = {EDP-Sciences},
     volume = {13},
     number = {2},
     year = {2007},
     doi = {10.1051/cocv:2007017},
     mrnumber = {2306639},
     zbl = {1124.49012},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/cocv:2007017/}
}