Perhaps you should try some spelling variations:
"50 ngn decrease" » "50 nn decrease" (Expand Search), "50 mean decrease" (Expand Search), "50 a decrease" (Expand Search), "50 ngnn decrease" (Expand Search), "50 nga decrease" (Expand Search), "50 ng_ decreased" (Expand Search), "50 ng decrease" (Expand Search), "50 nsgn decrease" (Expand Search), "50 nggn decrease" (Expand Search), "50 μgn decrease" (Expand Search)
"50 nsn decrease" » "50 nn decrease" (Expand Search), "50 mean decrease" (Expand Search), "50 use decreased" (Expand Search), "50 nsnn decrease" (Expand Search), "50 nsa decrease" (Expand Search), "50 ns_ decreased" (Expand Search), "50 ns decrease" (Expand Search), "50 nssn decrease" (Expand Search), "50 ngsn decrease" (Expand Search), "50 μsn decrease" (Expand Search)
"50 n decrease" » "50 nn decrease" (Expand Search), "50 a decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 ns decrease" (Expand Search), "50 ng decrease" (Expand Search), "50 μ 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: "((((((\"50 _ decrease\") OR (\"50 ngn decrease\"))) OR (\"50 nsn decrease\"))) OR (\"50 n decrease\"))~".
• Removing quotes may allow a broader search: (((((( 50 _ decrease ) OR ( 50 ngn decrease ))) OR ( 50 nsn decrease ))) OR ( 50 n decrease ))~.
• Adding a wildcard symbol may retrieve word variants: (((((("50 _ decrease") OR ("50 ngn decrease"))) OR ("50 nsn decrease"))) OR ("50 n decrease"))*.