Perhaps you should try some spelling variations:
passiv » passive, massiv, passiver
passivieren » passiveieren, massivieren, passiverieren, passivierende, passivierung, passagieren
passiven » passiveen, massiven, passiveren, passive
passieren » passiert
massiver » massive, massiven, passiver

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