- Author: Paul J.J. Welfens (editor)
- Language: German
- Year: 2020
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- Language: German
- Year: 2011
- Author: Dieter Cassel (editor), Paul J.J. Welfens (editor)
- Language: German
- Year: 2003
- Author: Thomas Apolte (editor), Rolf Caspers (editor), Paul J.J. Welfens (editor)
- Language: German
- Year: 2004