Perhaps you should try some spelling variations:
"improving contract performance metrics." » "improving country performance metrics.", "improving court performance metrics.", "improving corporate performance metrics.", "improving contract performance contracts.", "improving contract performance measures.", "improving contract performance contract.", "improve contract performance metrics.", "improving central performance metrics.", "improving coverage performance metrics."
"improving air performance series." » "improving air performance reviews.", "improving air performance review.", "improving air performance targets.", "improving firm performance series.", "improving a performance series.", "improving ii performance series.", "improving water performance series.", "improving land performance series.", "improving _ performance series."

Try widening your search to All Fields.

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