Perhaps you should try some spelling variations:
"improving voluntary performance review." » "improving country performance review.", "improving entry performance review.", "improving budgetary performance review.", "improving voluntary performance risk.", "improving voluntary performance evidence."
"improving loan performance series." » "improving loan performance metrics.", "improving loan performance reviews.", "improving loan performance targets.", "improving poor performance series.", "improving bank performance series.", "improving _ performance series.", "improving local performance series.", "improving land performance series.", "improving road 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 loan performance series.") or ("improving voluntary performance review."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving loan performance series.") OR ("improving voluntary performance review.")).
• Removing quotes may allow a broader search: (( improving loan performance series. ) or ( improving voluntary performance review. )).
• Adding a wildcard symbol may retrieve word variants: (("improving loan performance series.") or ("improving voluntary performance review."))*.