@book{DietrichLiebersBergstedt1998,
  author    = {Dietrich, Volkmar and Liebers, Klaus and Bergstedt, Christel},
  title     = {Naturwissenschaften : Biologie, Chemie, Physik : Bd. 3 Boden},
  editor    = {Dietrich, Volkmar},
  publisher = {Volk-und-Wissen-Verl.},
  address   = {Berlin},
  isbn      = {3-464-85176-1},
  pages     = {64 S.},
  year      = {1998},
  language  = {de}
}
@book{DietrichLiebers1998,
  author    = {Dietrich, Volkmar and Liebers, Klaus},
  title     = {Naturwissenschaften : Biologie, Chemie, Physik : Bd. 1 Farben},
  editor    = {Dietrich, Volkmar and Bergstedt, Christel and Liebers, Klaus},
  publisher = {Volk-und-Wissen-Verl.},
  address   = {Berlin},
  isbn      = {3-06-030966-3},
  pages     = {64 S.},
  year      = {1998},
  language  = {de}
}