Perhaps you should try some spelling variations:
passiv » massiv, passiver
passiven » massiven, passiveren, passion
passive » massive, passivere
passivieren » massivieren, passiverieren, passivierende, passivierung, passieren
passiverwerb » massiverwerb, passivererwerb
passiverer » massiverer, passivererer, passiver, passieren, passagerer

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 ((passiven OR passive) OR passivieren)) OR (passiverwerb OR passiverer)).
• Adding a wildcard symbol may retrieve word variants: ((passiv or ((passiven or passive) or passivieren)) or (passiverwerb or passiverer))*.