Perhaps you should try some spelling variations:
passiv » massiv, passiven
passive » massive, passivene
passiverer » massiverer, passivenerer, passiverwerb, passieren, passagerer, passivener, passierter
passivieren » massivieren, passivenieren, passivierende, passivierung, passieren
passiver » massiver, passivener, passiven, passiert
passively » massively, passivenely, passivity, passiven

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