@Article{ 
  leomora,
  author = { Leoni, Giovanni and Morini, Massimiliano },
  title = { Necessary and sufficient conditions for the chain rule in $W_{loc}^{1,1}(R^N;R^d)$ and $BV_{loc}(R^N;R^d)$ },
  journal = { J. Eur. Math. Soc. (JEMS) },
  year = { 2007 },
  volume = { 9 },
  number = { 2 },
  pages = { 219-252 },
  URL = { http://cvgmt.sns.it/paper/199/ },
  note = { cvgmt preprint}
}