Perhaps you should try some spelling variations:
passiv » passive, massiv, passiver
passiven » passiveen, massiven, passiveren, passive, passion
passiverwerb » passiveerwerb, massiverwerb, passivererwerb, passiverer
passieren » passiert
massiven » massive, massively, massiv

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