Perhaps you should try some spelling variations:
passiver » passiven, passively, passiert
passiveren » passivenen, passivelyen, passierten, passivieren, passieren, passiverer
passivelyen » passively
passivierende » passivierender, passivieren, aktivierende

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