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