Perhaps you should try some spelling variations:
passiv » passive, passiver
passiven » passiveen, passiveren, passive, passion
passiveen » passiveeen, passivereen, passiveand, passiverer, passive
passivieren » passiveieren, passiverieren, passivierende, passivierung, passieren
massiv » massive

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