@Misc{ 
  Afe20,
  author = { Afeltra, Claudio },
  title = { Singular solutions of the Yamabe problem in the Heisenberg group and their bifurcation },
  journal = {  },
  year = { 2020 },
  doi = { https://doi.org/10.48550/arXiv.2012.12706 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/6018/ },
  note = { cvgmt preprint}
}