@Article{ 
  BarDeS13,
  author = { Barchiesi, Marco and DeSimone, Antonio },
  title = { Frank energy for nematic elastomers: a nonlinear model },
  journal = { ESAIM: COCV },
  year = { 2015 },
  doi = { doi:10.1051/cocv/2014022 },
  volume = { 21 },
  number = { 2 },
  pages = { 372–377 },
  URL = { http://cvgmt.sns.it/paper/2217/ },
  note = { cvgmt preprint}
}