Perhaps you should try some spelling variations:
decrease regressive » decrease aggressive (Expand search), decrease depression (Expand search), increase aggressive (Expand search)
regressive effect » suppressive effect (Expand search), progressive effort (Expand search), expressive effects (Expand search)
decrease akt » decrease at (Expand search), decrease and (Expand search), decrease after (Expand search)
akt decrease » and decrease (Expand search), not decrease (Expand search), any decrease (Expand search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease akt decrease _ decrease ) OR ( decrease AND decrease regressive effect ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease akt decrease _ decrease ) OR ( decrease AND decrease regressive effect ))*.