@article{OtteRaetzelSipmanetal.2000,
  author    = {Otte, Volker and R{\"a}tzel, Stefan and Sipman, Harri J. M. and Kummer, Volker},
  title     = {Bemerkenswerte Flechtenfunde aus Brandenburg V},
  year      = {2000},
  language  = {de}
}
@article{RaetzelKummerOtteetal.2002,
  author    = {R{\"a}tzel, Stefan and Kummer, Volker and Otte, Volker and Sipman, Harri J. M},
  title     = {Bemerkenswerte Flechtenfunde aus Brandenburg VII},
  year      = {2002},
  language  = {de}
}