Perhaps you should try some spelling variations:
"improving urban performance series." » "improving urban performance studies.", "improving urban performance size.", "improving bank performance series.", "improving loan performance series.", "improving human performance series."
"improving sharia performance based." » "improving sharia performances based.", "improving sharing performance based.", "improving chart performance based.", "improving shared performance based.", "improving spatial performance based.", "improving static performance based."

You may be able to get more results by adjusting your search query.

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