Perhaps you should try some spelling variations:
passiv » passiven
passive » passivene
passiverer » passivenerer, passiverwerb, passivieren, passieren, passivener, passivelyer, passierter
passiver » passivener, passiven, passively, passiert
passivener » passivenener, passiven, passiverwerb

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