@book{BuderRichterWeinert2001,
  author    = {Buder, Margret and Richter, Dieter and Weinert, G.},
  title     = {Geografie : Arbeitsheft Klasse 5 ; Ausgabe Mecklenburg-Vorpommern},
  publisher = {Volk-und-Wissen-Verl.},
  address   = {Berlin},
  isbn      = {3-06-040574-3},
  pages     = {32 S.},
  year      = {2001},
  language  = {de}
}
@book{BuderRichterWeinert2001,
  author    = {Buder, Margret and Richter, Dieter and Weinert, G.},
  title     = {Geografie : Arbeitsheft Klasse 5 ; Ausgabe Sachsen},
  publisher = {Volk-und-Wissen-Verl.},
  address   = {Berlin},
  isbn      = {3-06-040573-5},
  pages     = {32 S.},
  year      = {2001},
  language  = {de}
}
@book{BuderRichterWeinert2001,
  author    = {Buder, Margret and Richter, Dieter and Weinert, G.},
  title     = {Geografie : Arbeitsheft Klasse 5 ; Ausgabe Th{\"u}ringen},
  publisher = {Volk und Wissen},
  address   = {Berlin},
  isbn      = {3-06-040575-2},
  year      = {2001},
  language  = {de}
}