@article{MTA_2018_3_1_a8,
     author = {C\u{a}lin \c{S}erban},
     title = {Multiple solutions of {Neumann} systems of relativistic type},
     journal = {Minimax theory and its applications},
     year = {2018},
     volume = {3},
     number = {1},
     zbl = {1392.35124},
     url = {http://geodesic.mathdoc.fr/item/MTA_2018_3_1_a8/}
}