- Author: Rüdiger Graf
- Language: English
- Year: 2018
- Author: Rüdiger Graf
- Language: German
- Year: 2014
- Author: Rüdiger Graf
- Language: German
- Year: 2014
- Author: Rüdiger Graf
- Language: German
- Year: 2008
- Author: Constantin Goschler, Rüdiger Graf
- Language: German
- Year: 2010
- Author: Rüdiger Graf
- Language: English
- Year: 2018