Perhaps you should try some spelling variations:
"improving company performance evidence." » "improving loan performance evidence.", "improving corporate performance evidence.", "improving contract performance evidence.", "improving human performance evidence."
"improving country performance series." » "improving country performance metrics.", "improving country performance reviews.", "improving country performance review.", "improving voluntary performance series.", "importing country performance series.", "borrowing country 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 country performance series.") or ("improving company performance evidence."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving country performance series.") OR ("improving company performance evidence.")).
• Removing quotes may allow a broader search: (( improving country performance series. ) or ( improving company performance evidence. )).
• Adding a wildcard symbol may retrieve word variants: (("improving country performance series.") or ("improving company performance evidence."))*.