Perhaps you should try some spelling variations:
passiver » passiven, passively, passiert
passivere » passivene, passivelye, passierte, passiverer, massivere, passivieren
passierte » passiert, klassierte, passieren
passioniert » passionierte, passionierter, passionierten
passivener » passiverer, 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: ((passiver OR passive) OR (((passivere OR passierte) OR passioniert) OR passivener)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiver or passive) or (((passivere OR passierte) or passioniert) or passivener))".
• Adding a wildcard symbol may retrieve word variants: ((passiver or passive) or (((passivere OR passierte) or passioniert) or passivener))*.