Perhaps you should try some spelling variations:
"20 means decrease" » "20 mean decrease" (Expand Search), "20 deaths decreased" (Expand Search), "20 meann decrease" (Expand Search), "20 mea_ decrease" (Expand Search), "20 meawe decrease" (Expand Search), "_ means decrease" (Expand Search), "k means decrease" (Expand Search), "a means decrease" (Expand Search)
"50 ns decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 we decrease" (Expand Search), "50 ms decrease" (Expand Search), "50 ngs decrease" (Expand Search), "50 μs decrease" (Expand Search), "50 _s decrease" (Expand Search)
"50 a decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "50 μ decrease" (Expand Search), "50 c decrease" (Expand Search)
"50 n decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 ng decrease" (Expand Search), "50 μ 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 a decrease") OR ("20 means decrease"))) OR ("50 n decrease"))) OR ("50 ns decrease"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"50 a decrease\") OR (\"20 means decrease\"))) OR (\"50 n decrease\"))) OR (\"50 ns decrease\"))".
• Removing quotes may allow a broader search: (((((( 50 a decrease ) OR ( 20 means decrease ))) OR ( 50 n decrease ))) OR ( 50 ns decrease )).
• Adding a wildcard symbol may retrieve word variants: (((((("50 a decrease") OR ("20 means decrease"))) OR ("50 n decrease"))) OR ("50 ns decrease"))*.