Perhaps you should try some spelling variations:
"improving co performance metrics." » "improving co performance contracts.", "improving co performance measures.", "improving co performance contract.", "improving do performance metrics.", "improving crop performance metrics.", "improving job performance metrics.", "improving _ performance metrics.", "improving macro performance metrics.", "improving food performance metrics."
"improving upper performance series." » "improving upper performance reviews.", "improving upper performance review.", "improving upper performance targets.", "improving under performance series.", "improving support performance series.", "improving poor performance series.", "improving supply performance series.", "improving water performance series.", "improving power 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 upper performance series.") or ("improving co performance metrics."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving upper performance series.") OR ("improving co performance metrics.")).
• Removing quotes may allow a broader search: (( improving upper performance series. ) or ( improving co performance metrics. )).
• Adding a wildcard symbol may retrieve word variants: (("improving upper performance series.") or ("improving co performance metrics."))*.