Perhaps you should try some spelling variations:
decrease risk » decreased risk (Expand search), increase risk (Expand search), decrease in (Expand search)
risk decrease » risk decreases (Expand search), risk increase (Expand search), break decrease (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)
decrease or » decrease of (Expand search), decrease on (Expand search), decrease pro (Expand search)
or decrease » of decrease (Expand search), not decrease (Expand search), to decrease (Expand search)
in object » an object (Expand search), and object (Expand search)
en object » an object (Expand search)

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