@article{ARM_2002_38_3_a1,
     author = {Papageorgiou, Nikolaos S. and Yannakakis, Nikolaos},
     title = {Multiple solutions for nonlinear periodic problems with discontinuities},
     journal = {Archivum mathematicum},
     pages = {171--182},
     year = {2002},
     volume = {38},
     number = {3},
     mrnumber = {1921589},
     zbl = {1090.34035},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_2002_38_3_a1/}
}