@Article{ 
  MazRuf20,
  author = { Mazzoleni, Dario and Ruffini, Berardo },
  title = { A spectral shape optimization problem with a nonlocal competing term },
  journal = { Calc. Var. PDE },
  year = { 2020 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/4808/ },
  note = { cvgmt preprint}
}