Perhaps you should try some spelling variations:
"iag general performance series." » "iag federal performance series.", "iag senegal performance series.", "iag gendered performance series.", "iag general performance studies.", "iag general performance size."
"improving global performance series." » "improving global performance studies.", "improving global performance size.", "improving total performance series.", "improving regional performance series.", "improving fiscal performance series.", "improving growth performance series.", "providing global performance series."

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 global performance series.") OR ("iag general performance series."))~.
• Removing quotes may allow a broader search: (( improving global performance series. ) or ( iag general performance series. ))~.
• Adding a wildcard symbol may retrieve word variants: (("improving global performance series.") or ("iag general performance series."))*.