Perhaps you should try some spelling variations:
"improving external performance metrics." » "improving emotional performance metrics.", "improving materials performance metrics.", "improving sectoral performance metrics.", "improving external performance measures.", "improving maternal performance metrics.", "improving central performance metrics.", "improving federal performance metrics."
"improving thermal performance review." » "improving thermal performance risk.", "improving thermal performance evidence.", "improving animal performance review.", "improving erm performance review.", "improving federal performance review."

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

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