- Author: Paul J.J. Welfens
- Language: German
- Year: 2009
- Author: Paul J.J. Welfens
- Language: German
- Year: 2009
- Author: Paul J.J. Welfens (editor)
- Language: German
- Year: 2020
- Author: Paul J.J. Welfens (editor)
- Language: German
- Year: 2011
- Author: Paul J.J. Welfens
- Language: German
- Year: 2013
- Author: Paul J. J. Welfens, Samir Kadiric
- Language: German
- Year: 2018
- Author: Paul J.J. Welfens, Dora Borbély
- Language: German
- Year: 2009