Perhaps you should try some spelling variations:
"improving contract performance review." » "improving country performance review.", "improving court performance review.", "improving economic performance review.", "improve contract performance review.", "improving central performance review.", "improve contrast performance review.", "improving contract performance risk.", "improving contract performance evidence."
"improving social performance series." » "improving school performance series.", "improving fiscal performance series.", "improving financial performance series.", "improving social performance studies.", "improving social performance size."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving contract performance review.") OR ("improving social performance series."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving contract performance review.\") OR (\"improving social performance series.\"))".
• Removing quotes may allow a broader search: (( improving contract performance review. ) OR ( improving social performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving contract performance review.") OR ("improving social performance series."))*.