Perhaps you should try some spelling variations:
"improving human performance series." » "improving human performance metrics.", "improving human performance reviews.", "improving human performance review.", "improving loan performance series.", "improving thermal performance series.", "improving company performance series.", "improving urban performance series.", "improving rural performance series."
"Improving poor performance risk." » "Improving export performance risk.", "Improving sector performance risk.", "Improving _ performance risk.", "Improving poor performance size.", "Improving poor performance based.", "Improving poor performance _."
improving poor » improving power, improving food, improving indoor

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving human performance series.") or ("Improving poor performance risk."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving human performance series.") OR ("Improving poor performance risk.")).
• Removing quotes may allow a broader search: (( improving human performance series. ) or ( Improving poor performance risk. )).
• Adding a wildcard symbol may retrieve word variants: (("improving human performance series.") or ("Improving poor performance risk."))*.