@book{BaumgaertelLledo2000,
  author    = {Baumg{\"a}rtel, Hellmut and Lled{\´o}, Fernando},
  title     = {Dual group actions on C*-algebras and their description by Hilbert extensions},
  series = {Preprint / SFB 288, Differentialgeometrie und Quantenphysik},
  volume    = {445},
  journal   = {Preprint / SFB 288, Differentialgeometrie und Quantenphysik},
  publisher = {Techn. Univ.},
  address   = {Berlin},
  pages     = {14 S.},
  year      = {2000},
  language  = {en}
}