Perhaps you should try some spelling variations:
massiv » massive
passiver » passiven, passively, passiert
aktivierende » motivierende, praktizierende, motivierenden, aktivierungde
aktivierenden » motivierenden, praktizierenden, motivierendenn, aktivierungden, motivierende
aktivieren » aktivierung, motivieren

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