Perhaps you should try some spelling variations:
passiven » passive, passion
passivenener » passiveener, passionener, passivierender, passiverer
passiverwerb » passiverer
passiveere » passivieren, passiver, massivere

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