Perhaps you should try some spelling variations:
base preprocessing » based preprocessing (Expand search), image preprocessing (Expand search), noise preprocessing (Expand search)
decrease faster » decrease after (Expand search), decrease further (Expand search), decreased after (Expand search)
faster decrease » rate decrease (Expand search)
decreased base » decreased bone (Expand search), decreased fas (Expand search), decreased rate (Expand search)
not decreased » not decrease (Expand search), to decreased (Expand search), not increased (Expand search)
decrease not » decrease of (Expand search), decrease at (Expand search), decrease akt (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 decreased base preprocessing ) OR ( decrease faster decrease NOT decrease ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease not decreased base preprocessing ) OR ( decrease faster decrease NOT decrease ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease not decreased base preprocessing ) OR ( decrease faster decrease NOT decrease ))*.