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

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