@Article{ 
  boucri,
  author = { Bouchut, François and Crippa, Gianluca },
  title = { Uniqueness, renormalization and smooth approximations for linear transport equations },
  journal = { SIAM J. Math. Anal. },
  year = { 2006 },
  volume = { 38 },
  number = { 4 },
  pages = { 1316-1328 },
  URL = { http://cvgmt.sns.it/paper/846/ },
  note = { cvgmt preprint}
}