Perhaps you should try some spelling variations:
and preprocessing » and reprocessing (Expand search), based preprocessing (Expand search), data preprocessing (Expand search)
decrease ratio » decreased ratio (Expand search), decrease at (Expand search), decreased rate (Expand search)
ratio decrease » rate decrease (Expand search), brazil decrease (Expand search), to decrease (Expand search)
decrease with » decreases with (Expand search), increase with (Expand search), decrease in (Expand search)
with decrease » with decreased (Expand search), with deceased (Expand search), with increase (Expand search)
decrease and » decreases and (Expand search), decrease in (Expand search), decrease of (Expand search)
decrease toc » decrease of (Expand search), decrease the (Expand search), decreased to (Expand search)
toc decrease » to decrease (Expand search), the decrease (Expand search), not 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 with decrease AND preprocessing ) OR ( decrease toc decrease ratio decrease ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease with decrease and preprocessing ) OR ( decrease toc decrease ratio decrease ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease with decrease and preprocessing ) OR ( decrease toc decrease ratio decrease ))*.