Perhaps you should try some spelling variations:
passiv » passiven
passiver » passivener, passiven, passively, passiert
passiverer » passivenerer, passivener, passivelyer, passierter, passiverwerb, passivieren, passieren
passive » passivene
massiven » passiven, massively

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