Perhaps you should try some spelling variations:
"improving loan performance studies." » "improving loan performance audits.", "improving loan performance audit.", "improving loan performance standards.", "improving local performance studies.", "improving land performance studies.", "improving lead performance studies."
"improving animal performance series." » "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."

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