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."
"improve port performance series." » "improve port performance studies.", "improve port performance size.", "improve export performance series.", "improve court performance series.", "improve plant performance series.", "improve post performance series.", "improve cost performance series.", "improve poor 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: (("improve port performance series.") or ("improving rural performance metrics."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improve port performance series.") OR ("improving rural performance metrics.")).
• Removing quotes may allow a broader search: (( improve port performance series. ) or ( improving rural performance metrics. )).
• Adding a wildcard symbol may retrieve word variants: (("improve port performance series.") or ("improving rural performance metrics."))*.