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