@book{Witt2005,
  author    = {Kurt-Ulrich Witt},
  title     = {Algebraische Grundlagen der Informatik},
  series = {Studium},
  edition   = {2., {\"u}berarbeitete Auflage},
  publisher = {Vieweg},
  address   = {Wiesbaden},
  isbn      = {3-528-13166-7},
  year      = {2005},
  language  = {de}
}