@Article{ 
  MazTreVel20,
  author = { Mazzoleni, Dario and Trey, Baptiste and Velichkov, Bozhidar },
  title = { Regularity of the optimal sets for the second Dirichlet eigenvalue },
  journal = { Ann. Inst. H. Poincaré Anal. Non Linéaire },
  year = { 2022 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/4839/ },
  note = { cvgmt preprint}
}