Perhaps you should try some spelling variations:
passiv » passive, massiv, passiver
passiven » passiveen, massiven, passiveren, passive, passion
passiverer » passiveerer, massiverer, passivererer, passiverwerb, passivieren, passiver
massivere » massiver, massive, massively
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 passiven) OR (passiverer OR massivere)) OR aktivierende).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((passiv OR passiven) or (passiverer or massivere)) or aktivierende)".
• Adding a wildcard symbol may retrieve word variants: (((passiv OR passiven) or (passiverer or massivere)) or aktivierende)*.