@book{BartowskiKaraszPfeiffer1999,
  author    = {Bartowski, Karin and Karasz, C. and Pfeiffer, S.},
  title     = {B{\"u}cherwurm - Mein Sprachbuch [4. Schuljahr] : Mein Arbeitsheft},
  editor    = {Ahlgrimm, Helga},
  publisher = {Klett},
  address   = {Leipzig},
  pages     = {64 S.},
  year      = {1999},
  language  = {de}
}
@book{Bartowski1997,
  author    = {Bartowski, Karin},
  title     = {B{\"u}cherwurm - Mein Sprachbuch [2. Schuljahr] : Mein Arbeitsheft ; Ausgabe f{\"u}r Berlin, Brandenburg, Mecklenburg-Vorpommmern, Sachsen, Sachsen-Anhalt},
  editor    = {Ahlgrimm, Helga},
  publisher = {Klett},
  address   = {Leipzig},
  pages     = {47 S.},
  year      = {1997},
  language  = {de}
}
@book{Bartowski1999,
  author    = {Bartowski, Karin},
  title     = {B{\"u}cherwurm - Mein Sprachbuch [4. Schuljahr] : [Lehrerband]},
  editor    = {Ahlgrimm, Helga},
  publisher = {Klett},
  address   = {Leipzig},
  year      = {1999},
  language  = {de}
}