Perhaps you should try some spelling variations:
"improving human performance review." » "improving human performance risk.", "improving human performance evidence.", "improving loan performance review.", "improving company performance review.", "improving animal performance review.", "improving urban performance review.", "improving rural performance review."
"improving thermal performance risks." » "improving maternal performance risks.", "improving rural performance risks.", "improving mental performance risks.", "improving thermal performance risk.", "improving thermal performance issues.", "improving thermal performance based."

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