Perhaps you should try some spelling variations:
"improving senegal performance series." » "improving general performance series.", "improving federal performance series.", "improving sectoral performance series.", "improving senegal performance studies.", "improving senegal performance size.", "improving central performance series.", "improving legal performance series."
"improving urban performance evidence." » "improving bank performance evidence.", "improving loan performance evidence.", "improving human performance evidence."

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