Perhaps you should try some spelling variations:
"improving rural performance based." » "improving pupil performance based.", "improving thermal performance based.", "improving overall performance based.", "improving rural performance measures.", "improving urban performance based.", "improving social performance based."
"improving can performance evidence." » "improving bank performance evidence.", "improving loan performance evidence.", "improving care performance evidence.", "improving land performance evidence.", "improving tax performance evidence.", "improving co performance evidence."

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

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