Perhaps you should try some spelling variations:
passiven » passive, passion
massiv » massive
massiveeren » massiveeeren, massivere, passivieren, massigeren
passiveren » passivieren, passieren, passiver
passiverer » passiverwerb, passivieren, passiver
massiger » massinger, massive, massie

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 massiv) OR ((passiveren OR passiverer) OR (massiger OR massiveeren))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiven or massiv) or ((passiveren OR passiverer) or (massiger or massiveeren)))".
• Adding a wildcard symbol may retrieve word variants: ((passiven or massiv) or ((passiveren OR passiverer) or (massiger or massiveeren)))*.