Perhaps you should try some spelling variations:
"50 nsga decrease" » "50 a decrease" (Expand Search), "50 nn decrease" (Expand Search), "50 msga decrease" (Expand Search), "50 ngsga decrease" (Expand Search), "50 μsga decrease" (Expand Search), "50 _sga decrease" (Expand Search)
"50 ns decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 a decrease" (Expand Search), "50 ms decrease" (Expand Search), "50 ngs decrease" (Expand Search), "50 μs decrease" (Expand Search), "50 _s decrease" (Expand Search)
"50 n decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 a decrease" (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 nsga decrease") OR ((("50 n decrease") OR ("50 ns decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"50 nsga decrease\") OR (((\"50 n decrease\") OR (\"50 ns decrease\"))))".
• Removing quotes may allow a broader search: (( 50 nsga decrease ) OR ((( 50 n decrease ) OR ( 50 ns decrease )))).
• Adding a wildcard symbol may retrieve word variants: (("50 nsga decrease") OR ((("50 n decrease") OR ("50 ns decrease"))))*.