@article{KoehlerKlunterRaudies2005,
  author    = {K{\"o}hler, Egon and Klunter, Martina and Raudies, Monika},
  title     = {Veranschaulichungen beim L{\"o}sen von Sachaufgaben : Beobachtungen bei Viertkl{\"a}sslern},
  year      = {2005},
  language  = {de}
}
@article{KlunterRaudiesKoehler2005,
  author    = {Klunter, Martina and Raudies, Monika and K{\"o}hler, Egon},
  title     = {Veranschaulichungen beim L{\"o}sen von Sachaufgaben-Beobachtungen bei Vierkl{\"a}sslern},
  year      = {2005},
  language  = {de}
}
@article{KlunterRaudies2005,
  author    = {Klunter, Martina and Raudies, Monika},
  title     = {Sachrechnen und Differenzierung},
  year      = {2005},
  language  = {de}
}
@article{KlunterRaudies2005,
  author    = {Klunter, Martina and Raudies, Monika},
  title     = {K{\"a}fer Kunis Knobeleien},
  year      = {2005},
  language  = {de}
}