Perhaps you should try some spelling variations:
"improving public performance series." » "improving building performance series.", "improving specific performance series.", "improving public performance metrics.", "improving public performance reviews.", "improving public performance review.", "improving quality performance series."
"improving past performance risk." » "improving plant performance risk.", "improving port performance risk.", "improving based performance risk.", "improving past performance size.", "improving past performance based.", "improving past performance _.", "improving basic performance risk.", "improving asset performance risk.", "improving land 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 public performance series.") or ("improving past performance risk."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving public performance series.") OR ("improving past performance risk.")).
• Removing quotes may allow a broader search: (( improving public performance series. ) or ( improving past performance risk. )).
• Adding a wildcard symbol may retrieve word variants: (("improving public performance series.") or ("improving past performance risk."))*.