Perhaps you should try some spelling variations:
"50 ngsn decrease" » "50 nn decrease" (Expand Search), "50 mean decrease" (Expand Search), "50 ngsnn decrease" (Expand Search), "50 ngs_ decrease" (Expand Search), "50 ngs_ decreased" (Expand Search), "50 nsgsn decrease" (Expand Search), "50 nggsn decrease" (Expand Search), "50 μgsn 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 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 a decrease\") OR (\"50 ngsn decrease\"))) OR (\"50 n decrease\"))~".
• Removing quotes may allow a broader search: (((( 50 a decrease ) OR ( 50 ngsn decrease ))) OR ( 50 n decrease ))~.
• Adding a wildcard symbol may retrieve word variants: (((("50 a decrease") OR ("50 ngsn decrease"))) OR ("50 n decrease"))*.