Perhaps you should try some spelling variations:
passiv » massiv
passiver » massiver, passiert
passivener » massivener, passiverer, passiverwerb, passioner
passiven » massiven, passion
passively » massively, passivity
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 passiver) OR ((passivener OR passiven) OR passively)) OR massive) OR passive).
• Adding a wildcard symbol may retrieve word variants: ((((passiv or passiver) or ((passivener or passiven) or passively)) or massive) or passive)*.