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 mental performance measures." » "improving general performance measures.", "improving senegal performance measures.", "improving annual performance measures.", "improving maternal performance measures.", "improving fiscal performance measures.", "improving gender 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 mental performance measures.") OR ("improving human performance reviews."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving mental performance measures.\") OR (\"improving human performance reviews.\"))".
• Removing quotes may allow a broader search: (( improving mental performance measures. ) OR ( improving human performance reviews. )).
• Adding a wildcard symbol may retrieve word variants: (("improving mental performance measures.") OR ("improving human performance reviews."))*.