Perhaps you should try some spelling variations:
passiv » passive, massiv, passiver
passivieren » passiveieren, massivieren, passiverieren, passivierende, passivierung, passagieren
passiven » passiveen, massiven, passiveren, passive, passion
passiverer » passiveerer, massiverer, passivererer, passiverwerb, passiver, passagerer
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 ((passivieren OR passiven) OR (passiverer OR passieren))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(passiv or ((passivieren or passiven) or (passiverer OR passieren)))".
• Adding a wildcard symbol may retrieve word variants: (passiv or ((passivieren or passiven) or (passiverer OR passieren)))*.