- Author: Axel Schulz, Waldemar Berg, Marco A. Gardini, Torsten Kirstges, Bernd Eisenstein
- Language: German
- Year: 2011
- Author: Waldemar Berg
- Language: German
- Year: 2013
- Author: Axel Schulz, Waldemar Berg, Marco A. Gardini, Torsten Kirstges, Bernd Eisenstein
- Language: German
- Year: 2013
- Author: Waldemar Berg
- Language: German
- Year: 2008
- Author: Waldemar Berg
- Language: German
- Year: 2011