Perhaps you should try some spelling variations:
passiver » passive, passiven, passively
passiveren » passiveen, passivenen, passivelyen, passivieren, passieren, passiven
passiverer » passiveer, passivener, passivelyer, passiverwerb, passivieren, passieren
massiv » massive
massiveeren » massiveeeren, massivere, passivieren, massivdecken
passiveneren » passivieren, passieren
massigeren » massiger, massigen, massivere

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