@Article{ 
  butste04,
  author = { Buttazzo, Giuseppe and Stepanov, Eugene },
  title = { Minimization problems for average distance functionals },
  journal = { Calculus of Variations: Topics from the Mathematical Heritage of Ennio De Giorgi, D. Pallara (ed.), Quaderni di Matematica, Seconda Universit\`{a} di Napoli, Caserta },
  year = { 2004 },
  volume = { 14 },
  pages = { 47-83 },
  URL = { http://cvgmt.sns.it/paper/166/ },
  note = { cvgmt preprint}
}