Perhaps you should try some spelling variations:
passiv » massiv, passiven, passiver
passive » massive, passivene, passivere
passivieren » massivieren, passivenieren, passiverieren, passivierende, passivierung, passieren
massivere » massiver, massive, massively
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 passive) OR (passivieren OR massivere)) OR aktivierenden).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((passiv OR passive) or (passivieren or massivere)) or aktivierenden)".
• Adding a wildcard symbol may retrieve word variants: (((passiv OR passive) or (passivieren or massivere)) or aktivierenden)*.