Perhaps you should try some spelling variations:
passiv » massiv, passiven, passiver
passive » massive, passivene, passivere
passivieren » massivieren, passivenieren, passiverieren, passivierende, passivierung, passagieren
passiverwerb » massiverwerb, passivenerwerb, passivererwerb, passiverer
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 passive) OR passivieren) OR (passiverwerb OR passieren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((passiv OR passive) or passivieren) or (passiverwerb or passieren))*".