Perhaps you should try some spelling variations:
"improving human performance issues." » "improving human performance based.", "improving human performance size.", "improving human performance index.", "improving loan performance issues.", "improving thermal performance issues.", "improving company performance issues.", "improving urban performance issues.", "improving rural performance issues."
"improving can performance measures." » "improving bank performance measures.", "improving loan performance measures.", "improving care performance measures.", "improving land performance measures.", "improving tax performance measures.", "improving co performance measures."

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

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