- Author: Norbert Frei Christoph Schlienkamp (auth.)
- Language: German
- Year: 1999
- Author: Anton Schmoll (auth.)
- Language: German
- Year: 1992
- Author: Reiner Brehler (auth.)
- Language: German
- Year: 1998
- Author: Dirk Schneider (auth.)
- Language: German
- Year: 2001