@Article{ 
  dallaz09,
  author = { Dal Maso, Gianni and Lazzaroni, Giuliano },
  title = { Crack growth with non-interpenetration: a simplified proof for the pure Neumann problem },
  journal = { Discrete Contin. Dyn. Syst. (DCDS-A) },
  year = { 2011 },
  volume = { 31 },
  number = { 4 },
  pages = { 1219-1231 },
  URL = { http://cvgmt.sns.it/paper/1223/ },
  note = { cvgmt preprint}
}