Perhaps you should try some spelling variations:
"improving rural performance metrics." » "improving rural performance measures.", "improving euract performance metrics.", "improving larval performance metrics.", "improving pupil performance metrics."
"improving basic performance series." » "improving basic performance studies.", "improving basic performance size.", "improving based performance series.", "improving music performance series.", "improving baseline performance series.", "improving air performance series.", "improve basic 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 basic performance series.") or ("improving rural performance metrics."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving basic performance series.") OR ("improving rural performance metrics.")).
• Removing quotes may allow a broader search: (( improving basic performance series. ) or ( improving rural performance metrics. )).
• Adding a wildcard symbol may retrieve word variants: (("improving basic performance series.") or ("improving rural performance metrics."))*.