Perhaps you should try some spelling variations:
"improving contract performance series." » "improving country performance series.", "improving court performance series.", "improving corporate performance series.", "improve contract performance series.", "improving central performance series.", "improving coverage performance series.", "improving contract performance metrics.", "improving contract performance reviews.", "improving contract performance review."
"improving food performance evidence." » "improving good performance evidence.", "improving poor performance evidence.", "improving fund performance evidence.", "improving land performance evidence."

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