Perhaps you should try some spelling variations:
passiv » passive, passiver
passiven » passiveen, passiveren, passive, passion
passiveren » passiveeren, passivereren, passivieren, passiver, passageren
passiverer » passiveerer, passivererer, passiverwerb, passivieren, passiver
massiv » massive
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 ((passiveren OR passieren) OR passiverer))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiv or massiv) or (passiven or ((passiveren OR passieren) or passiverer)))".
• Adding a wildcard symbol may retrieve word variants: ((passiv or massiv) or (passiven or ((passiveren OR passieren) or passiverer)))*.