Perhaps you should try some spelling variations:
passiv » passive, passiven, passiver
passiverer » passiveerer, passivenerer, passivererer, passiverwerb, passiver, passieren
passivieren » passiveieren, passivenieren, passiverieren, passivierende, passivierung, passieren
massiv » massive
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 massiv) OR (passiverer OR (massigeren OR passivieren))).
• Adding a wildcard symbol may retrieve word variants: ((passiv or massiv) or (passiverer or (massigeren or passivieren)))*.