Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivere » passiveere, massivere, passivenere, passiver, passivieren
passiverer » passiveerer, massiverer, passivenerer, passiverr, passivierenr, 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 (passivere OR passiverer)) OR aktivierende).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiv or (passivere OR passiverer)) or aktivierende)".
• Adding a wildcard symbol may retrieve word variants: ((passiv or (passivere OR passiverer)) or aktivierende)*.