- Author: Luhmann Niklas
- Language: English
- Year: 1997
- Author: Luhmann Niklas
- Language: German
- Year: 1995
- Author: Luhmann Niklas
- Language: German
- Year: 2008
- Author: Luhmann Niklas, Hellmann Kai-Uwe (Hrsg.)
- Language: German
- Year: 1996
- Author: Luhmann Niklas, Barrett Rhodes
- Language: English, German
- Year: 2012
- Author: Luhmann Niklas
- Language: English
- Year: 1988