Perhaps you should try some spelling variations:
"improving based performance based." » "improving care performance based.", "improving board performance based.", "improving past performance based.", "improving based performance measures.", "improving basic performance based.", "improving shared performance based.", "improving water performance based."
"improving bank performance risk." » "improving market performance risk.", "improving _ performance risk.", "improving firm performance risk.", "improving bank performance size.", "improving bank performance _.", "improving bank performance data.", "improving land performance risk.", "improving urban performance risk.", "improving basic performance risk."

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: (("improving based performance based.") or ("improving bank performance risk."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving based performance based.") OR ("improving bank performance risk.")).
• Removing quotes may allow a broader search: (( improving based performance based. ) or ( improving bank performance risk. )).
• Adding a wildcard symbol may retrieve word variants: (("improving based performance based.") or ("improving bank performance risk."))*.