@article{HeroldGzik1991,
  author    = {Herold, H. and Gzik, Axel},
  title     = {Ver{\"a}nderungen im Stressmetabolismus von Beta vulgaris durch Benzyladenin},
  year      = {1991},
  language  = {de}
}
@article{Groenke1991,
  author    = {Gr{\"o}nke, Ottokar},
  title     = {Gesetzm{\"a}ßigkeiten in der Biologiedidaktik?},
  isbn      = {3-8142-0418-2},
  year      = {1991},
  language  = {de}
}