@Article{ 
  MetPalVes5,
  author = { Metafune, Giorgio and Pallara, Diego and Vespri, Vincenzo },
  title = { $L^p$-estimates for a class of elliptic operators with unbounded coefficients in ${\mathbb R}^n$ },
  journal = { Houston J. Math. },
  year = { 2005 },
  volume = { 31 },
  pages = { 605-620 },
  URL = { http://cvgmt.sns.it/paper/2399/ },
  note = { cvgmt preprint}
}