Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivieren » passiveieren, massivieren, passivenieren, passivierende, passivierung, passagieren
passiverwerb » passiveerwerb, massiverwerb, passivenerwerb
passiverer » passiveerer, massiverer, passivenerer, passiver, passagerer, massivere
passivenerwerb » passiveenerwerb, massivenerwerb, passivenenerwerb
passieren » passiert, 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: ((passiv OR passivieren) OR (((passiverwerb OR passiverer) OR passivenerwerb) OR passieren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiv or passivieren) or (((passiverwerb OR passiverer) or passivenerwerb) or passieren))*".