Perhaps you should try some spelling variations:
passiver » passive, passively, passiert
passiverer » passiveer, passivelyer, passierter, passiverwerb, passivieren, passieren
passiven » passive, passion
passivene » passivee, passione, passiveand, passive, passively

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: ((passiver OR passiven) OR (passivene OR passiverer)).
• Adding a wildcard symbol may retrieve word variants: ((passiver or passiven) or (passivene or passiverer))*.