@Article{ 
  butdepfra00,
  author = { Buttazzo, Giuseppe and De Pascale, Luigi and Fragalà, Ilaria },
  title = { Topological Equivalence of Some Variational Problems Involving Distances },
  journal = { Discrete Contin. Dinam. Systems },
  year = { 2001 },
  volume = { 7 },
  pages = { 247-258 },
  URL = { http://cvgmt.sns.it/paper/1022/ },
  note = { cvgmt preprint}
}