Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivieren » passiveieren, massivieren, passivenieren, passivierende, passieren, passagieren
passivierung » passiveierung, massivierung, passivenierung, aktivierung
massiveen » massiven, massivement, massivsten

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 (massiveen OR (passivieren OR passivierung))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(passiv or (massiveen or (passivieren OR passivierung)))".
• Adding a wildcard symbol may retrieve word variants: (passiv or (massiveen or (passivieren OR passivierung)))*.