Perhaps you should try some spelling variations:
"improving basic performance review." » "improving basic performance risk.", "improving basic performance evidence.", "improving based performance review.", "improving bank performance review.", "improving past performance review.", "improving air performance review.", "improve basic performance review.", "improving public performance review."
"improving social performance based." » "improving school performance based.", "improving fiscal performance based.", "improving financial performance based.", "improving social 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 basic performance review.") or ("improving social performance based."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving basic performance review.") OR ("improving social performance based.")).
• Removing quotes may allow a broader search: (( improving basic performance review. ) or ( improving social performance based. )).
• Adding a wildcard symbol may retrieve word variants: (("improving basic performance review.") or ("improving social performance based."))*.