Perhaps you should try some spelling variations:
"improving urban performance review." » "improving urban performance risk.", "improving urban performance evidence.", "improving bank performance review.", "improving loan performance review.", "improving human performance review."
"improving chain performance series." » "improving chain performance studies.", "improving chain performance size.", "improving loan performance series.", "improving managing performance series.", "improving brain performance series.", "improving caring performance series.", "improving air 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 urban performance review.") or ("improving chain performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving urban performance review.") OR ("improving chain performance series.")).
• Removing quotes may allow a broader search: (( improving urban performance review. ) or ( improving chain performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving urban performance review.") or ("improving chain performance series."))*.