- Author: Kathy Hennig Lars Ihring
- Language: German
- Year: 2013
- Author: Kathy Hennig Lars Ihring
- Language: German
- Year: 2012
- Author: Kathy Hennig, Lars Ihring, Michael Papendieck
- Language: German
- Year: 2010
- Author: Kathy Hennig Lars Ihring Michael Papendieck
- Language: German
- Author: Kathy Hennig Lars Ihring Michael Papendieck
- Language: German
- Year: 2010