Search for: [Subject and Keywords = Freshwater mussels \(Unionids, Najadeen\) \- Rhine \(river\)] OR [Subject and Keywords = Freshwater mussels \- river area fauna] OR [Subject and Keywords = Małże słodkowodne \- \(Unionidy, Najadeen\) \- Ren \(rzeka\)] OR [Subject and Keywords = Małże słodkowodne \- fauna obszaru rzek] OR [Title = Zur Erforschung der Najadeenfauna des Rheingebietes] OR [Creator = Kobelt, Wilhelm \(1840–1916\)]