Perhaps you should try some spelling variations:
"improving antenatal performance evidence." » "improving annual performance evidence.", "improving potential performance evidence.", "improving international performance evidence.", "improving mental performance evidence.", "providing antenatal performance evidence."
"improving thermal performance series." » "improving thermal performance studies.", "improving thermal performance size.", "improving external performance series.", "improving animal performance series.", "improving erm 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 thermal performance series.") or ("improving antenatal performance evidence."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving thermal performance series.") OR ("improving antenatal performance evidence.")).
• Removing quotes may allow a broader search: (( improving thermal performance series. ) or ( improving antenatal performance evidence. )).
• Adding a wildcard symbol may retrieve word variants: (("improving thermal performance series.") or ("improving antenatal performance evidence."))*.