Perhaps you should try some spelling variations:
"improving asset performance evidence." » "improving market performance evidence.", "improving based performance evidence.", "improving past performance evidence.", "improving sme performance evidence.", "improving adult performance evidence."
"improving high performance risk." » "improving high performance size.", "improving high performance based.", "improving high performance _.", "improving firm performance risk.", "improving _ performance risk.", "improving higher performance risk.", "improving hiv performance risk.", "improving birth performance risk."

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