Perhaps you should try some spelling variations:
passiv » passiven, passiver
passivierender » passivenierender, passiverierender, passivierende, aktivierender, passivieren
passive » passivene, passivere
massiv » massive
massiverwerb » massiveerwerb, passiverwerb, massivere, massierer

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