Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivenere » passiveenere, massivenere, passivenenere, passiverwerb
passiverer » passiveerer, massiverer, passivenerer, passiverwerb, passivieren, passiver
aktivierende » aktivierenden, 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: ((passiv OR (passivenere OR passiverer)) OR aktivierende).
• Adding a wildcard symbol may retrieve word variants: ((passiv or (passivenere or passiverer)) or aktivierende)*.