- Author: Professor Dr. Paul J. J. Welfens (auth.)
- Language: German
- Year: 2008
- Author: Professor Dr. Paul J.J. Welfens (auth.)
- Language: German
- Year: 2005
- Author: Kieran Mc Morrow Werner Roeger (auth.) Paul J. J. Welfens (eds.)
- Language: English
- Year: 2004