Perhaps you should try some spelling variations:
"improving general performance series." » "improving federal performance series.", "improving senegal performance series.", "improving gendered performance series.", "improving general performance studies.", "improving general performance size.", "improving central performance series.", "improving energy performance series."
"growing global performance series." » "growing global performance studies.", "growing global performance size.", "growing total performance series.", "growing regional performance series.", "growing fiscal performance series.", "going global 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 general performance series.") or ("growing global performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving general performance series.") OR ("growing global performance series.")).
• Removing quotes may allow a broader search: (( improving general performance series. ) or ( growing global performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving general performance series.") or ("growing global performance series."))*.