Perhaps you should try some spelling variations:
passiv » passive, massiv, passiver
passiverwerb » passiveerwerb, massiverwerb, passivererwerb, passiverer
passiven » passiveen, massiven, passiveren, passive, passion
passieren » passiert

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 (passieren OR passiverwerb)) OR passiven).
• Adding a wildcard symbol may retrieve word variants: ((passiv or (passieren or passiverwerb)) or passiven)*.