Perhaps you should try some spelling variations:
"improving rural performance reviews." » "improving rural performance review.", "improving rural performance reports.", "improving rural performance risks.", "improving euract performance reviews.", "improving larval performance reviews.", "improving pupil performance reviews."
"improving bank performance series." » "improving bank performance studies.", "improving bank performance size.", "improving urban performance series.", "improving basic performance series.", "improving brain 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 rural performance reviews.") or ("improving bank performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving rural performance reviews.") OR ("improving bank performance series.")).
• Removing quotes may allow a broader search: (( improving rural performance reviews. ) or ( improving bank performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving rural performance reviews.") or ("improving bank performance series."))*.