Perhaps you should try some spelling variations:
"5 ppm decrease" » "5 _ decrease" (Expand Search), "5 nn decrease" (Expand Search), "5 pa decreased" (Expand Search)
"5 026 decrease" » "5 _ decrease" (Expand Search), "5 nn decrease" (Expand Search), "n 026 decrease" (Expand Search)
"50 ms decrease" » "50 _ decrease" (Expand Search), "50 nn decrease" (Expand Search), "50 mean decrease" (Expand Search), "50 mg decrease" (Expand Search), "50 mm 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)

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: (((((("5 ppm decrease") OR ("5 026 decrease"))) OR ("50 ms decrease"))) OR ("50 a decrease"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"5 ppm decrease\") OR (\"5 026 decrease\"))) OR (\"50 ms decrease\"))) OR (\"50 a decrease\"))".
• Removing quotes may allow a broader search: (((((( 5 ppm decrease ) OR ( 5 026 decrease ))) OR ( 50 ms decrease ))) OR ( 50 a decrease )).
• Adding a wildcard symbol may retrieve word variants: (((((("5 ppm decrease") OR ("5 026 decrease"))) OR ("50 ms decrease"))) OR ("50 a decrease"))*.