@Misc{ 
  ambfig09,
  author = { Ambrosio, Luigi and Figalli, Alessio },
  title = { Almost everywhere well-posedness of continuity equations with measure initial data },
  journal = { C. R. Math. Acad. Sci. Paris },
  year = { 2010 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/1278/ },
  note = { cvgmt preprint}
}