Perhaps you should try some spelling variations:
passiv » passive, massiv, passiver
passiveeren » passiveeeren, massiveeren, passivereeren, passivieren, passieren, passivierende
passiverer » passiveerer, massiverer, passivererer, passiverwerb, passivieren, passiver
passiven » passiveen, massiven, passiveren, passive, passion

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