Perhaps you should try some spelling variations:
"improving social performance metrics." » "improving social performance measures.", "improving school performance metrics.", "improving fiscal performance metrics.", "improving financial performance metrics."
"improving pupil performance series." » "improving pupil performance studies.", "improving pupil performance size.", "improving model performance series.", "improving judicial performance series.", "improving public performance series.", "improving civil performance series.", "improving audit performance series."

Try widening your search to All Fields.

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

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