Perhaps you should try some spelling variations:
"improving social performance reviews." » "improving social performance review.", "improving social performance reports.", "improving social performance risks.", "improving school performance reviews.", "improving fiscal performance reviews.", "improving financial performance reviews."
"improving euract performance series." » "improving euract performance studies.", "improving euract performance size.", "improving act performance series.", "improving impact performance series.", "improving contract performance series.", "improving rural performance series.", "improving neural performance series.", "improving accuracy 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 euract performance series.") OR ("improving social performance reviews."))~.
• Removing quotes may allow a broader search: (( improving euract performance series. ) or ( improving social performance reviews. ))~.
• Adding a wildcard symbol may retrieve word variants: (("improving euract performance series.") or ("improving social performance reviews."))*.