@article{CMJ_2005__55_4_a1,
     author = {Gasi\'nski, Leszek and Papageorgiou, Nikolaos S.},
     title = {Extremal solutions and strong relaxation for second order multivalued boundary value problems},
     journal = {Czechoslovak Mathematical Journal},
     pages = {827--844},
     publisher = {mathdoc},
     volume = {55},
     number = {4},
     year = {2005},
     mrnumber = {2184366},
     zbl = {1081.34012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2005__55_4_a1/}
}