@Misc{ 
  til98,
  author = { Tilli, Paolo },
  title = { On a Constrained Variational Problem with an Arbitrary Number of Free Boundaries },
  journal = { Interfaces and Free Boundaries },
  year = { 1998 },
  volume = { 2 },
  number = { 2 },
  pages = { 201-212 },
  URL = { http://cvgmt.sns.it/paper/210/ },
  note = { cvgmt preprint}
}