Perhaps you should try some spelling variations:
"improving human performance measures." » "improving loan performance measures.", "improving thermal performance measures.", "improving company performance measures.", "improving urban performance measures.", "improving rural performance measures."
"improving firms performance risks." » "improving firm performance risks.", "improving firm performances risks.", "improving funds performance risks.", "improving firms performance risk.", "improving firms performance issues.", "improving firms performance based.", "improving farmers performance risks.", "improving air performance risks.", "improving birth performance risks."

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