- Author: Ute Koithan Helen Schmitz Tanja Sieber Ralf Sonntag
- Language: German
- Year: 2016
- Author: Ute Koithan Helen Schmitz Tanja Sieber Ralf Sonntag
- Language: German
- Year: 1
- Author: Ute Koithan, Tanja Mayr-Sieber, Helen Schmitz, Ralf Sonntag, Ralf-Peter Lösche
- Language: German
- Year: 2014
- Author: Stefanie Dengler Paul Rusch Helen Schmitz
- Language: German
- Year: 2013
- Author: Stefanie Dengler Paul Rusch Helen Schmitz
- Language: German
- Year: 2013