Perhaps you should try some spelling variations:
decrease operational » increase operational (Expand search), disease operational (Expand search), decrease cooperation (Expand search)
operational process » operational processes (Expand search), operacional processos (Expand search), operational problems (Expand search)
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 and » decreases and (Expand search), decrease in (Expand search), decrease of (Expand search)
and increase » and increases (Expand search), and increased (Expand search)
increase akt » increase at (Expand search), increase fast (Expand search), increase gait (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.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( decrease risk decrease operational process ) OR ( decrease AND increase akt decrease ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease risk decrease operational process ) OR ( decrease and increase akt decrease ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease risk decrease operational process ) OR ( decrease and increase akt decrease ))*.