Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivieren » passiveieren, massivieren, passivenieren, passivierende, passivierung, passieren
passiveieren » passiveeieren, massiveieren, passiveneieren, passionierten, passivierende, passieren
passiverwerb » passiveerwerb, massiverwerb, passivenerwerb, passiverer

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 passiveieren)) OR (passiverwerb OR passiert))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiv or (passivieren OR passiveieren)) or (passiverwerb or passiert))*".