Perhaps you should try some spelling variations:
"improving maternal performance measures." » "improving materials performance measures.", "improving external performance measures.", "improving national performance measures.", "improve maternal performance measures.", "improving water performance measures."
"improving rural performance review." » "improving rural performance risk.", "improving rural performance evidence.", "improving euract performance review.", "improving larval performance review.", "improving pupil performance review."

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 review.") or ("improving maternal performance measures."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving rural performance review.") OR ("improving maternal performance measures.")).
• Removing quotes may allow a broader search: (( improving rural performance review. ) or ( improving maternal performance measures. )).
• Adding a wildcard symbol may retrieve word variants: (("improving rural performance review.") or ("improving maternal performance measures."))*.