Perhaps you should try some spelling variations:
passiv » passive, passiver
passiven » passiveen, passiveren, passive, passion
passiveeren » passiveeeren, passivereeren, passivieren, passiverer, passivierende
massiv » massive
massigeren » massiger, massigen, massivere
passieren » passiert

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 (passiven OR (massigeren OR (passiveeren OR passieren)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiv or massiv) or (passiven or (massigeren or (passiveeren OR passieren))))".
• Adding a wildcard symbol may retrieve word variants: ((passiv or massiv) or (passiven or (massigeren or (passiveeren OR passieren))))*.