Perhaps you should try some spelling variations:
"_ fe decrease" » "_ _ decrease" (Expand Search), "_ e decrease" (Expand Search)
"_ eb decrease" » "_ _ decrease" (Expand Search), "_ web decrease" (Expand Search), "_ ebv decrease" (Expand Search), "_ ebm decrease" (Expand Search)
"5 a decrease" » "5 _ decrease" (Expand Search), "5 _ decreased" (Expand Search), "5 _ decreases" (Expand Search)
"a mean decrease" » "_ mean decrease" (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: "((\"5 a decrease\") OR (((\"a mean decrease\") OR (((\"_ fe decrease\") OR (\"_ eb decrease\"))))))~".
• Removing quotes may allow a broader search: (( 5 a decrease ) OR ((( a mean decrease ) OR ((( _ fe decrease ) OR ( _ eb decrease ))))))~.
• Adding a wildcard symbol may retrieve word variants: (("5 a decrease") OR ((("a mean decrease") OR ((("_ fe decrease") OR ("_ eb decrease"))))))*.