Perhaps you should try some spelling variations:
passiven » passive, passion
passiveren » passivieren, passieren, passiverer
massigeren » massiger, massivere, massierer
massigen » massiger, massige, massigung
passiveeren » passivieren, passieren, passiverer
passiveeeren » passivieren, passieren, passiverer

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