Perhaps you should try some spelling variations:
passiver » passive, passiven, passively
passivere » passivee, passivene, passivelye, passiverer, massivere, passivieren
massiv » massive
aktivierende » aktivieren, motivierende, praktizierende
aktivierenden » aktivierenn, motivierenden, praktizierenden, aktivieren, motivierende

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((passiver OR massiv) OR passivere) OR (aktivierende OR aktivierenden)).
• Adding a wildcard symbol may retrieve word variants: (((passiver or massiv) or passivere) or (aktivierende or aktivierenden))*.