- Author: Holger Wacker, Jürgen E. Blank
- Language: German
- Year: 1998
- Author: David L. Scott, Almut Oetjen, Ulrich Scheele, Holger Wacker
- Language: German
- Year: 2000
- Author: Holger Wacker, Jürgen Blank
- Language: German
- Year: 1999
- Author: Holger Wacker Frank Baeseler
- Language: German