Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivere » passiveere, massivere, passivenere, passiverer, passiver
passiveerer » passiveeerer, massiveerer, passiveneerer, passiverer, passivieren, passiverwerb
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 (passivere OR passiveerer)) OR aktivierende).
• Adding a wildcard symbol may retrieve word variants: ((passiv or (passivere or passiveerer)) or aktivierende)*.