Perhaps you should try some spelling variations:
"improving country performance review." » "improving country performance risk.", "improving country performance evidence.", "improving voluntary performance review.", "importing country performance review.", "borrowing country performance review."
"improving gender performance series." » "improving under performance series.", "improving better performance series.", "improving teacher performance series.", "improving gender performance metrics.", "improving gender performance reviews.", "improving gender performance targets.", "improving energy performance series.", "improving water performance series.", "improving land 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: (("improving country performance review.") or ("improving gender performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving country performance review.") OR ("improving gender performance series.")).
• Removing quotes may allow a broader search: (( improving country performance review. ) or ( improving gender performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving country performance review.") or ("improving gender performance series."))*.