Perhaps you should try some spelling variations:
decrease operation » decrease cooperation (Expand search), decrease migration (Expand search), decrease predation (Expand search)
operation process » operational process (Expand search), separation process (Expand search), generation process (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)
on decreased » in decreased (Expand search), of decreased (Expand search), on deceased (Expand search)
decrease on » decrease in (Expand search), decrease of (Expand search), decrease or (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 _ decrease operation process ) OR ( decrease akt decrease on decreased ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease _ decrease operation process ) OR ( decrease akt decrease on decreased ))*.