Perhaps you should try some spelling variations:
"20 means decrease" » "20 deaths decreased" (Expand Search), "_ means decrease" (Expand Search), "k means decrease" (Expand Search), "a means decrease" (Expand Search)
"50 mean decrease" » "50 a decrease" (Expand Search)
"5 ng decrease" » "5 nn decrease" (Expand Search), "5 _ decrease" (Expand Search), "5 a decrease" (Expand Search), "5 g decrease" (Expand Search), "5 nm decrease" (Expand Search), "5 kg decrease" (Expand Search)
"5 mg decrease" » "5 _ decrease" (Expand Search), "5 a decrease" (Expand Search), "5 nn decrease" (Expand Search), "5 mm 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 mean decrease") OR ("20 means decrease"))) OR ((("5 ng decrease") OR ("5 mg decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"50 mean decrease\") OR (\"20 means decrease\"))) OR (((\"5 ng decrease\") OR (\"5 mg decrease\"))))".
• Removing quotes may allow a broader search: (((( 50 mean decrease ) OR ( 20 means decrease ))) OR ((( 5 ng decrease ) OR ( 5 mg decrease )))).
• Adding a wildcard symbol may retrieve word variants: (((("50 mean decrease") OR ("20 means decrease"))) OR ((("5 ng decrease") OR ("5 mg decrease"))))*.