Perhaps you should try some spelling variations:
"improving city performance review." » "improving city performance evidence.", "improving firm performance review.", "improving high performance review.", "improving key performance review.", "improving its performance review.", "improving equity performance review.", "improving birth performance review."
"improving country performance risk." » "improving voluntary performance risk.", "importing country performance risk.", "borrowing country performance risk.", "improving country performance size.", "improving country performance based.", "improving country performance _."

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

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