Perhaps you should try some spelling variations:
"improving country performance metrics." » "improving voluntary performance metrics.", "importing country performance metrics.", "improving community performance metrics."
"improving thermal performance measures." » "improving external performance measures.", "improving animal performance measures.", "improving erm 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 country performance metrics.") or ("improving thermal performance measures."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving country performance metrics.") OR ("improving thermal performance measures."))*.
• Removing quotes may allow a broader search: (( improving country performance metrics. ) or ( improving thermal performance measures. ))*.