Perhaps you should try some spelling variations:
"improving animal performance series." » "improving animal performance studies.", "improving animal performance size.", "improving annual performance series.", "improving thermal performance series.", "improving fiscal performance series.", "improving initial performance series.", "improving optimal performance series.", "improving criminal performance series."
"improving plant performance evidence." » "improving port performance evidence.", "improving court performance evidence.", "improving land performance evidence.", "improving place performance evidence.", "improved plant performance evidence."

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