Perhaps you should try some spelling variations:
ppm decrease » _ decrease (Expand Search)
we decrease » _ decrease (Expand Search)
wt decrease » _ decrease (Expand Search)
n decrease » _ decrease (Expand Search), _ decreased (Expand Search), _ decreases (Expand Search)
50 n » 50 _ (Expand Search), 50 i (Expand Search)
_ we » _ web (Expand Search), _ e (Expand Search), _ fe (Expand Search)
5 wt » _ wt (Expand Search), 5 ht (Expand Search), 2 wt (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 ppm decrease ) OR ((( 50 n decrease ) OR ((( _ we decrease ) OR ( 5 wt decrease ))))))~".
• Adding a wildcard symbol may retrieve word variants: (( 50 ppm decrease ) OR ((( 50 n decrease ) OR ((( _ we decrease ) OR ( 5 wt decrease ))))))*.