@book{BalzerBeegerHallermannetal.2002,
  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 3 : Gymnasium Rheinland-Pfalz},
  publisher = {Schroedel},
  address   = {Hannover},
  isbn      = {3-507-52607-7},
  pages     = {176 S.},
  year      = {2002},
  language  = {de}
}
@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}
}