Perhaps you should try some spelling variations:
passiv » massiv, passiven, passiver
passiveren » massiveren, passiveneren, passivereren, passivieren, passieren, passiven
passiverer » massiverer, passivenerer, passivererer, passiverwerb, passivieren, passiver
passive » massive, passivene, passivere

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