Perhaps you should try some spelling variations:
decrease shadowing » decrease owing (Expand search), decrease following (Expand search), decreases shedding (Expand search)
shadowing effect » shadowing effects (Expand search), shading effect (Expand search), shading effects (Expand search)
decrease that » decrease the (Expand search), decrease at (Expand search), decrees that (Expand search)
that decrease » that increase (Expand search), that increases (Expand search), not decrease (Expand search)
decrease and » decreases and (Expand search), decrease in (Expand search), decrease of (Expand search)
and decrease » and decreases (Expand search), and decreased (Expand search), and increase (Expand search)
decrease low » decreases low (Expand search), decreases flow (Expand search), decrease of (Expand search)
low decrease » flow decrease (Expand search), loss decrease (Expand search), to 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 that decrease AND decrease ) OR ( decrease low decrease shadowing effect ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease that decrease and decrease ) OR ( decrease low decrease shadowing effect ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease that decrease and decrease ) OR ( decrease low decrease shadowing effect ))*.