- Author: Christina Morina, Marianne Birthler, Norbert Frei, Philipp Ther, Ton Nijhuis
- Language: German
- Year: 2021
- Author: Norbert Frei, Joel Golb, Fritz Stern
- Language: English
- Year: 2002
- Author: Norbert Frei (editor)
- Language: German
- Year: 1991
- Author: Norbert Frei
- Language: German
- Year: 2010
- Author: Norbert Frei Christoph Schlienkamp (auth.)
- Language: German
- Year: 1999
- Author: Norbert Frei
- Language: English
- Year: 2002
