@Article{ 
  BraDefVit97,
  author = { Braides, Andrea and Defranceschi, Anneliese and Vitali, Enrico },
  title = { A relaxation approach to Hencky's plasticity },
  journal = { Applied Math. Optim. },
  year = { 1997 },
  doi = { 10.1007/BF02683319 },
  volume = { 35 },
  pages = { 45-68 },
  URL = { http://cvgmt.sns.it/paper/3756/ },
  note = { cvgmt preprint}
}