Perhaps you should try some spelling variations:
passiv » massiv, passiven, passiver
passive » massive, passivene, passivere
passiverer » massiverer, passivenerer, passivererer, passivieren, passiver, passieren
passiverwerb » massiverwerb, passivenerwerb, passivererwerb

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 (passiverer OR passiverwerb))).
• Adding a wildcard symbol may retrieve word variants: (passiv or (passive or (passiverer or passiverwerb)))*.