Perhaps you should try some spelling variations:
"improving human performance reviews." » "improving human performance review.", "improving human performance reports.", "improving human performance risks.", "improving loan performance reviews.", "improving thermal performance reviews.", "improving chain performance reviews."
"improving legal performance series." » "improving legal performance studies.", "improving legal performance size.", "improving level performance series.", "improving senegal performance series.", "improving global performance series.", "improving local performance series.", "improving lead performance series."

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