Perhaps you should try some spelling variations:
passiv » massiv, passiver
passive » massive, passivere
passivener » massivener, passiverener, passiverer, passiver, passioner
passiverwerb » massiverwerb, passivererwerb, passiverer
passiven » massiven, passiveren, passion

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