Perhaps you should try some spelling variations:
quark effective » are effective (Expand search), equally effective (Expand search)
decrease quark » decrease fear (Expand search), decrease work (Expand search), decrease quality (Expand search)
decrease not » decrease of (Expand search), decrease akt (Expand search), decrease at (Expand search)
not decrease » to decrease (Expand search), not increase (Expand search), and decrease (Expand search)
decrease may » decrease at (Expand search), decrease by (Expand search), decrease human (Expand search)
may decrease » may increase (Expand search), can decrease (Expand search), to decrease (Expand search)
in decrease » in decreased (Expand search), on decrease (Expand search), pain 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 decrease may decrease ) OR ( decrease in decrease quark effective ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease not decrease may decrease ) OR ( decrease in decrease quark effective ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease not decrease may decrease ) OR ( decrease in decrease quark effective ))*.