Perhaps you should try some spelling variations:
passiv » massiv
passiven » massiven, passion
passiver » massiver, passively
passiverer » massiverer, passivelyer, passiverwerb, passivieren, passieren
passive » massive

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