@Article{ 
  Sol13,
  author = { Solombrino, Francesco },
  title = { A-priori time regularity estimates and a simplified proof of existence in perfect plasticity },
  journal = { Mathematische Nachrichten },
  year = { 2015 },
  doi = { 10.1002/mana.201300110 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2139/ },
  note = { cvgmt preprint}
}