Perhaps you should try some spelling variations:
"20 means decrease" » "20 mean decrease" (Expand Search), "20 deaths decreased" (Expand Search), "_ means decrease" (Expand Search), "k means decrease" (Expand Search), "i means decrease" (Expand Search)
"a means decrease" » "a mean decrease" (Expand Search), "a deaths decreased" (Expand Search), "_ means decrease" (Expand Search), "k means decrease" (Expand Search)
"50 nn decrease" » "50 _ decrease" (Expand Search), "50 a decrease" (Expand Search), "50 mean decrease" (Expand Search), "50 ns decrease" (Expand Search), "50 ng decrease" (Expand Search), "50 n decrease" (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("50 nn decrease") OR ((("20 means decrease") OR ("a means decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"50 nn decrease\") OR (((\"20 means decrease\") OR (\"a means decrease\"))))".
• Removing quotes may allow a broader search: (( 50 nn decrease ) OR ((( 20 means decrease ) OR ( a means decrease )))).
• Adding a wildcard symbol may retrieve word variants: (("50 nn decrease") OR ((("20 means decrease") OR ("a means decrease"))))*.