@Misc{ 
  chlciafus02,
  author = { Chlebik, Miroslav and Cianchi, Andrea and Fusco, Nicola },
  title = { The perimeter inequality for Steiner symmetrization: cases of equality },
  journal = {  },
  year = { 2002 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/89/ },
  note = { cvgmt preprint}
}