@Article{ 
  PaoTor18,
  author = { Paolini, Emanuele and Tortorelli, Vincenzo Maria },
  title = { The quadruple planar bubble enclosing equal areas is symmetric },
  journal = { Calc. Var. },
  year = { 2020 },
  doi = { 10.1007/s00526-019-1687-9 },
  volume = { 59 },
  number = { 1 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/4089/ },
  note = { cvgmt preprint}
}