Perhaps you should try some spelling variations:
"50 mean decrease" » "50 a decrease" (Expand Search), "50 meann decrease" (Expand Search), "50 mea_ decrease" (Expand Search), "50 meaa decrease" (Expand Search), "20 means decrease" (Expand Search)
"50 n decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 a decrease" (Expand Search), "50 ns decrease" (Expand Search), "50 ng decrease" (Expand Search), "50 μ decrease" (Expand Search)
"50 meannn decrease" » "50 meannnn decrease" (Expand Search), "50 meann_ decrease" (Expand Search), "50 meanna decrease" (Expand Search), "20 meansnn 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 n decrease") OR ((("50 mean decrease") OR ("50 meannn decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"50 n decrease\") OR (((\"50 mean decrease\") OR (\"50 meannn decrease\"))))".
• Removing quotes may allow a broader search: (( 50 n decrease ) OR ((( 50 mean decrease ) OR ( 50 meannn decrease )))).
• Adding a wildcard symbol may retrieve word variants: (("50 n decrease") OR ((("50 mean decrease") OR ("50 meannn decrease"))))*.