Perhaps you should try some spelling variations:
"improving country performance metrics." » "improving country performance contracts.", "improving country performance measures.", "improving country performance contract.", "improving voluntary performance metrics.", "importing country performance metrics.", "borrowing country performance metrics."
"improving firm performance evidence." » "improving _ performance evidence.", "improving firms performance evidence.", "improving air performance evidence.", "improving birth performance evidence."

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