Perhaps you should try some spelling variations:
passiv » passive, massiv, passiven
passiveerer » passiveeerer, massiveerer, passiveneerer, passiverer, passiverwerb
passivieren » passiveieren, massivieren, passivenieren, passivierende, passivierung, passieren
massiveren » massivere, massigeren, massiven

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 (massiveren OR massivement)) OR (passiveerer OR passivieren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((passiv or (massiveren or massivement)) or (passiveerer OR passivieren))*".