@Misc{ 
  MicAnt21,
  author = { Henrot, Antoine and Michetti, Marco },
  title = { A comparison between Neumann and Steklov eigenvalues },
  journal = { Journal of Spectral Theory },
  year = { 2021 },
  pages = { 30 },
  URL = { http://cvgmt.sns.it/paper/5203/ },
  note = { cvgmt preprint}
}