Perhaps you should try some spelling variations:
passiv » passive, massiv, passiver
passiven » passiveen, massiven, passiveren, passive, passion
passiveeer » passiveeeer, massiveeer, passivereeer, passiver, passiverwerb
passiverer » passiveerer, massiverer, passivererer, passiverwerb, passivieren, passiver

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