@Article{ 
  DacMarPao12,
  author = { Dacorogna, Bernard and Marcellini, Paolo and Paolini, Emanuele },
  title = { The two well problem for piecewise affine maps },
  journal = { Adv. Differential Equations },
  year = { 2012 },
  volume = { 17 },
  number = { 7/8 },
  pages = { 673--696 },
  URL = { http://cvgmt.sns.it/paper/1758/ },
  note = { cvgmt preprint}
}