Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passivieren » passiveieren, massivieren, passivenieren, passivierende, passivierung, passieren
massiveren » massivere, massivement, massiven
massigeren » massiger, massigen, massivere

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 (massiveren OR massigeren))).
• Adding a wildcard symbol may retrieve word variants: (passiv or (passivieren or (massiveren or massigeren)))*.