- Author: Müller Gunter
- Language: German
- Year: 1993
- Author: Fedders Wolfgang
- Language: German
- Year: 1993
- Author: Eickmans Heinz, Schueren Gert van der
- Language: German
- Year: 1986
- Author: Maerlant Jacob van, Sodmann Timothy
- Language: German
- Year: 1980
- Author: Eichhoff Jürgen
- Language: German
- Year: 1968