Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivieren » passiveieren, massivieren, passivenieren, passivierende, passivierung, passieren
passiverwerb » passiveerwerb, massiverwerb, passivenerwerb, passiverer
massiverer » massivere, massierer, 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 passiverwerb)) OR massiverer)*.