Perhaps you should try some spelling variations:
passiven » passive, passion
passivene » passivee, passione, passiverer, passive, passively
passivierende » passivierender, aktivierende, passivierung, passivierungde, passierende, passagierende
passivieren » passivierung, passieren, passagieren

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