Perhaps you should try some spelling variations:
passiv » massiv, passiver
passiven » massiven, passiveren, passion
passive » massive, passivere
passiverer » massiverer, passivererer, passiverwerb, passivieren, passiver
passivener » massivener, passiverener, passioner, passiver, passiverwerb

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