Perhaps you should try some spelling variations:
"improving plant performance risk." » "improving bank performance risk.", "improving loan performance risk.", "improving port performance risk.", "improving plant performance size.", "improving plant performance based.", "improving plant performance _.", "improving land performance risk.", "improving laws performance risk.", "improving payment performance risk."
"improving air performance risk." » "improving air performance size.", "improving air performance based.", "improving air performance _.", "improving firm performance risk.", "improving a performance risk.", "improving ii performance risk.", "improving water performance risk.", "improving land performance risk.", "improving _ performance risk."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving air performance risk.") OR ("improving plant performance risk."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving air performance risk.\") OR (\"improving plant performance risk.\"))".
• Removing quotes may allow a broader search: (( improving air performance risk. ) OR ( improving plant performance risk. )).
• Adding a wildcard symbol may retrieve word variants: (("improving air performance risk.") OR ("improving plant performance risk."))*.