Perhaps you should try some spelling variations:
"improving contract performance metrics." » "improving country performance metrics.", "improving court performance metrics.", "improving economic performance metrics.", "improving contract performance measures.", "improve contract performance metrics.", "improving central performance metrics.", "improve contrast performance metrics."
"improving based performance series." » "improving based performance studies.", "improving based performance size.", "improving board performance series.", "improving fund performance series.", "improving good performance series.", "improving basic performance series.", "improving care performance series.", "improving asset performance series."

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 metrics.") OR ("improving based performance series."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving contract performance metrics.\") OR (\"improving based performance series.\"))".
• Removing quotes may allow a broader search: (( improving contract performance metrics. ) OR ( improving based performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving contract performance metrics.") OR ("improving based performance series."))*.