- Author: Christian Hillen
- Language: German
- Year: 2012
- Author: Joachim Oepen, Christian Hillen, Birgit Lambert
- Language: German
- Year: 2021
- Author: Christian Hillen, Michael Kaiser, Stefan Wunsch
- Language: German
- Year: 2019
- Author: Christian Hillen, Joachim Oepen, Wolfgang Rosen
- Language: German
- Year: 2022
- Author: Christian Hillen
- Language: German
- Year: 2016