Perhaps you should try some spelling variations:
"significantly impaired decrease" » "significantly improved decrease" (Expand Search), "significantly improve decrease" (Expand Search), "significantly improves decrease" (Expand Search), "significantly marked decrease" (Expand Search)
"significantly smaller decrease" » "significantly larger decrease" (Expand Search), "significantly shorter decrease" (Expand Search), "significantly higher decrease" (Expand Search), "significantly small decrease" (Expand Search), "significantly marked decrease" (Expand Search), "significantly smaller areas" (Expand Search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"significantly smaller decrease\") OR (\"significantly impaired decrease\"))~".
• Removing quotes may allow a broader search: (( significantly smaller decrease ) OR ( significantly impaired decrease ))~.
• Adding a wildcard symbol may retrieve word variants: (("significantly smaller decrease") OR ("significantly impaired decrease"))*.