Perhaps you should try some spelling variations:
"improving birth performance review." » "improving birth performance evidence.", "improving firm performance review.", "improving high performance review.", "improving port performance review.", "improving air performance review.", "improving health performance review.", "improving growth performance review."
"improving asset performance risk." » "improving market performance risk.", "improving based performance risk.", "improving past performance risk.", "improving asset performance size.", "improving asset performance based.", "improving asset performance _.", "improving sme performance risk.", "improving adult performance risk."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving birth performance review.") or ("improving asset performance risk."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving birth performance review.") OR ("improving asset performance risk.")).
• Removing quotes may allow a broader search: (( improving birth performance review. ) or ( improving asset performance risk. )).
• Adding a wildcard symbol may retrieve word variants: (("improving birth performance review.") or ("improving asset performance risk."))*.