Perhaps you should try some spelling variations:
passiv » passive, passiven, passiver
passiveeren » passiveeeren, passiveneeren, passivereeren, passivieren, passieren, passiverer
massiv » massive
massiveeren » massiveeeren, passivieren, massivdecken, massivteilen
massivere » massiveere, massiver, massive, massively
massigeren » massiger, massigen, massierer

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