Perhaps you should try some spelling variations:
"improving pupil performance series." » "improving pupil performance studies.", "improving pupil performance size.", "improving social performance series.", "improving model performance series.", "improving judicial performance series.", "improving public performance series.", "improving civil performance series.", "improving audit performance series."
"improving fiscal performance series." » "improving fiscal performance studies.", "improving fiscal performance size.", "improving financial 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 pupil performance series.") or ("improving fiscal performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving pupil performance series.") OR ("improving fiscal performance series.")).
• Removing quotes may allow a broader search: (( improving pupil performance series. ) or ( improving fiscal performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving pupil performance series.") or ("improving fiscal performance series."))*.