Perhaps you should try some spelling variations:
passiven » passive, passion
massiv » massive
massiveren » massiveeren, massivere, massigeren, passivieren
massivement » massiveement
massiveeren » massiveeeren, massivere, passivieren, massigeren
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: ((passiven OR massiv) OR (passieren OR ((massiveren OR massivement) OR massiveeren))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiven or massiv) or (passieren or ((massiveren OR massivement) or massiveeren)))".
• Adding a wildcard symbol may retrieve word variants: ((passiven or massiv) or (passieren or ((massiveren OR massivement) or massiveeren)))*.