- Author: Schwerdtfeger Gunther
- Language: German
- Year: 1990
- Author: Schnieders Michael
- Language: German
- Year: 1996
- Author: Schimmele Tanja
- Language: German
- Year: 2020
- Author: Roeser Thomas
- Language: German
- Year: 1988
- Author: Neckermann Gerhard, Wessels Hans
- Language: German
- Year: 1988
- Author: Mock Erhard
- Language: German
- Year: 1983
- Author: Kolotouros Panagiotis
- Language: German
- Year: 1992
- Author: Kelnhofer Evelyn
- Language: German
- Year: 1994