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 chain performance series." » "improving chain performance studies.", "improving chain performance size.", "improving loan performance series.", "improving managing performance series.", "improving brain performance series.", "improving caring performance series.", "improving air 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 chain performance series.") or ("improving rural performance metrics."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving chain performance series.") OR ("improving rural performance metrics.")).
• Removing quotes may allow a broader search: (( improving chain performance series. ) or ( improving rural performance metrics. )).
• Adding a wildcard symbol may retrieve word variants: (("improving chain performance series.") or ("improving rural performance metrics."))*.