Perhaps you should try some spelling variations:
"improving urban performance reviews." » "improving urban performance review.", "improving urban performance reports.", "improving urban performance risks.", "improving bank performance reviews.", "improving loan performance reviews.", "improving human performance reviews."
"improving eco performance series." » "improving eco performance studies.", "improving eco performance size.", "improving do performance series.", "improving ceo performance series.", "improving core performance series.", "improving co performance series.", "improving e performance series.", "improving eap 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 reviews.") or ("improving eco performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving urban performance reviews.") OR ("improving eco performance series.")).
• Removing quotes may allow a broader search: (( improving urban performance reviews. ) or ( improving eco performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving urban performance reviews.") or ("improving eco performance series."))*.