Perhaps you should try some spelling variations:
"improving quality performance series." » "improving utility performance series.", "improving safety performance series.", "improving city performance series.", "improving quality performance metrics.", "improving quality performance reviews.", "improving quality performance review.", "improving health performance series."
"improving bank performance risk." » "improving market performance risk.", "improving _ performance risk.", "improving firm performance risk.", "improving bank performance size.", "improving bank performance based.", "improving bank performance _.", "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 quality performance series.") or ("improving bank performance risk."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving quality performance series.") OR ("improving bank performance risk.")).
• Removing quotes may allow a broader search: (( improving quality performance series. ) or ( improving bank performance risk. )).
• Adding a wildcard symbol may retrieve word variants: (("improving quality performance series.") or ("improving bank performance risk."))*.