Perhaps you should try some spelling variations:
passiv » massiv
passive » massive
passiven » massiven, passion
passiverer » massiverer, passiverwerb, passivieren, passieren, passivelyer, passierter
passiver » massiver, passively, 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 passive) OR (((passiven OR massiven) OR passiverer) OR passiver)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiv or passive) or (((passiven OR massiven) or passiverer) or passiver))".
• Adding a wildcard symbol may retrieve word variants: ((passiv or passive) or (((passiven OR massiven) or passiverer) or passiver))*.