Perhaps you should try some spelling variations:
decrease flying » decrease flooding (Expand search), decrease walking (Expand search), decrease during (Expand search)
decrease their » decrease the (Expand search), increase their (Expand search), decreases the (Expand search)
their decrease » the decrease (Expand search), their disease (Expand search), the decreased (Expand search)
flying objects » moving objects (Expand search), flying insects (Expand search)
decrease not » decrease of (Expand search), decrease akt (Expand search), decrease at (Expand search)
not increase » and increase (Expand search), an increase (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 NOT increase akt decrease ) OR ( decrease their decrease flying objects ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease not increase akt decrease ) OR ( decrease their decrease flying objects ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease not increase akt decrease ) OR ( decrease their decrease flying objects ))*.