Perhaps you should try some spelling variations:
passiver » passive, passiven, passively
passiveren » passiveen, passivenen, passivelyen, passivieren, passieren, passiven
passiverer » passiveer, passivener, passivelyer, passiverwerb, passivieren, passieren
passiveand » passiven

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