Perhaps you should try some spelling variations:
"5 ppm decrease" » "5 _ decrease" (Expand Search)
"i wt decrease" » "i _ decrease" (Expand Search), "_ wt decrease" (Expand Search), "i et decrease" (Expand Search), "2 wt decrease" (Expand Search)
"5 ht decrease" » "5 _ decrease" (Expand Search)
"10 a decrease" » "10 _ decrease" (Expand Search), "10 _ decreased" (Expand Search), "10 _ decreases" (Expand Search), "19 a decrease" (Expand Search), "1 a decrease" (Expand Search)

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 ((("10 a decrease") OR ((("i wt decrease") OR ("5 ht decrease"))))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"5 ppm decrease\") OR (((\"10 a decrease\") OR (((\"i wt decrease\") OR (\"5 ht decrease\"))))))*".
• Removing quotes may allow a broader search: (( 5 ppm decrease ) OR ((( 10 a decrease ) OR ((( i wt decrease ) OR ( 5 ht decrease ))))))*.