@article{FresardKopp2012,
  author    = {Raymond Fr{\´e}sard and Thilo Kopp},
  title     = {Exact results with the Kotliar-Ruckenstein slave-boson representation},
  journal   = {Annalen der Physik},
  volume    = {524},
  number    = {3-4},
  pages     = {175 -- 181},
  doi       = {10.1002/andp.201100197},
  year      = {2012},
}