@Article{ 
  leotil06,
  author = { Leonardi, Gian Paolo and Tilli, Paolo },
  title = { On a constrained variational problem in the vector-valued case },
  journal = { J. Math. Pures Appl. },
  year = { 2006 },
  volume = { 85 },
  pages = { 251-268 },
  URL = { http://cvgmt.sns.it/paper/870/ },
  note = { cvgmt preprint}
}