@article{COCV_2007__13_1_93_0,
     author = {Gangbo, Wilfrid and Oliker, Vladimir},
     title = {Existence of optimal maps in the reflector-type problems},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     pages = {93--106},
     publisher = {EDP-Sciences},
     volume = {13},
     number = {1},
     year = {2007},
     doi = {10.1051/cocv:2006017},
     mrnumber = {2282103},
     zbl = {1136.49015},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/cocv:2006017/}
}