Perhaps you should try some spelling variations:
"improving pupil performance metrics." » "improving pupil performance measures.", "improving social performance metrics.", "improving model performance metrics.", "improving judicial performance metrics.", "improving public performance metrics.", "improving civil performance metrics.", "improving audit performance metrics."
"improving thermal performance series." » "improving thermal performance studies.", "improving thermal performance size.", "improving external performance series.", "improving animal performance series.", "improving erm performance series."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving thermal performance series.") or ("improving pupil performance metrics."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving thermal performance series.") OR ("improving pupil performance metrics."))*.
• Removing quotes may allow a broader search: (( improving thermal performance series. ) or ( improving pupil performance metrics. ))*.