Perhaps you should try some spelling variations:
passiven » passive, passion
passiveneer » passiveeer, passioneer, passiverer
passively » massively, passive, passivity
passiveen » passivieren, passiverer, passive
massiven » massive, massively, massiv
passiverwerb » passiverer

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: (((passiven OR passively) OR ((passiveen OR passiveand) OR massiven)) OR (passiveneer OR passiverwerb)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((passiven or passively) or ((passiveen or passiveand) or massiven)) or (passiveneer OR passiverwerb))".
• Adding a wildcard symbol may retrieve word variants: (((passiven or passively) or ((passiveen or passiveand) or massiven)) or (passiveneer OR passiverwerb))*.