Perhaps you should try some spelling variations:
passiver » passive, passiert
passively » massively, passive, passivity
passiven » passive, passion
massiveren » massivere, massivement, passivieren
massigeren » massiger, massigen, massivere
passiveeren » passivieren, passieren, 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: ((passiver OR passively) OR (passiven OR ((massiveren OR massigeren) OR passiveeren))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiver OR passively) or (passiven or ((massiveren or massigeren) or passiveeren)))".
• Adding a wildcard symbol may retrieve word variants: ((passiver OR passively) or (passiven or ((massiveren or massigeren) or passiveeren)))*.