@book{BalzerBeegerHallermannetal.2001,
  author    = {Balzer, Werner and Beeger, Helmut and Hallermann, Sigrun and Kirsch, H. and Nicklaus, W. and Robel, B. and Werner-Tokarski, D. and Herzig, Reinhard},
  title     = {Seydlitz Geographie 2 : Gymnasium Rheinland-Pfalz, Saarland},
  publisher = {Schroedel},
  address   = {Hannover},
  isbn      = {3-507-52606-9},
  pages     = {224 S.},
  year      = {2001},
  language  = {de}
}
@book{BoettcherMingenbachMuelleretal.2001,
  author    = {B{\"o}ttcher, Kirsten and Mingenbach, Hans-Michael and M{\"u}ller, Helmut and Starke, Rainer and Waldeck, Winfried and Wehrs, Klaus and Herzig, Reinhard},
  title     = {Seydlitz Geographie 1 : Kl. 7/8, Sch{\"u}lerband, Niedersachsen},
  publisher = {Schroedel},
  address   = {Braunschweig},
  isbn      = {3-507-52608-5},
  pages     = {224 S.},
  year      = {2001},
  language  = {de}
}
@article{Herzig2001,
  author    = {Herzig, Reinhard},
  title     = {Evaluation of cartographic educational software for children},
  isbn      = {7-5030-1018- 5},
  year      = {2001},
  language  = {en}
}