Perhaps you should try some spelling variations:
passiv » passiven, passiver
passive » passivene, passivere
passiverer » passivenerer, passivererer, passiverwerb, passivieren, passiver
massiv » massive
aktivierende » aktivierenden, aktivieren, motivierende
aktivierenn » aktivieren, aktivierend, aktivierenden

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