@Article{ 
  BarFel15,
  author = { Bardi, Martino and Feleqi, Ermal },
  title = { Nonlinear Elliptic Systems and Mean Field Games },
  journal = { NoDEA Nonlinear Differential  Equations Appl. },
  year = { 2016 },
  doi = { 10.1007/s00030-016-0397-7 },
  volume = { 23 },
  number = { 4 },
  pages = {  23--44 },
  URL = { http://cvgmt.sns.it/paper/2655/ },
  note = { cvgmt preprint}
}