Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivierende » passiveierende, massivierende, passivenierende, passivierender, passivieren, aktivierende
passiverwerb » passiveerwerb, massiverwerb, passivenerwerb, passiverer
massivieren » passivieren, massigeren, passivierung
massivere » massiver, massive, massively

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 (passivierende OR massivieren)) OR (passiverwerb OR massivere)).
• Adding a wildcard symbol may retrieve word variants: ((passiv or (passivierende or massivieren)) or (passiverwerb or massivere))*.