Perhaps you should try some spelling variations:
passiven » passive, passion
massivieren » massivere, massigeren, passivierende
massivierung » passivierung, passivierungs, massierung
massiveren » massivere, massigeren, massivement
passivieren » passivierende, passivierung, passieren

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: (passiven OR ((massivieren OR massivierung) OR (massiveren OR passivieren))).
• Adding a wildcard symbol may retrieve word variants: (passiven or ((massivieren or massivierung) or (massiveren or passivieren)))*.