Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
massivierende » passivierende, passivierender, passivierenden
massivere » massiver, massive, massively
aktivierenden » motivierende, aktivierungden, motivierenden
aktivieren » aktivierung, motivieren

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 (massivierende OR massivere)) OR (aktivierenden OR aktivieren)).
• Adding a wildcard symbol may retrieve word variants: ((passiv or (massivierende or massivere)) or (aktivierenden or aktivieren))*.