- Author: Udo Friedrich
- Language: German
- Year: 2008
- Author: Manfred Eikelmann (editor), Udo Friedrich (editor)
- Language: German
- Year: 2013
- Author: Udo Friedrich (editor), Bruno Quast (editor)
- Language: German
- Year: 2004
- Author: Udo Friedrich (editor), Ulrich Hoffmann (editor), Bruno Quast (editor)
- Language: German
- Year: 2020
- Author: Udo Friedrich (editor), Ulrich Hoffmann (editor), Bruno Quast (editor)
- Language: German
- Year: 2020
- Author: Udo Friedrich (editor), Andreas Hammer (editor), Christiane Witthöft (editor)
- Language: German
- Year: 2013