Perhaps you should try some spelling variations:
"improving basic performance metrics." » "improving basic performance measures.", "improving based performance metrics.", "improving music performance metrics.", "improving baseline performance metrics.", "improving air performance metrics.", "improve basic performance metrics."
"improving basic performance evidence." » "improving based performance evidence.", "improving music performance evidence.", "improving baseline performance evidence.", "improving air performance evidence.", "improve basic 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 basic performance metrics.") or ("improving basic performance evidence."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving basic performance metrics.") OR ("improving basic performance evidence.")).
• Removing quotes may allow a broader search: (( improving basic performance metrics. ) or ( improving basic performance evidence. )).
• Adding a wildcard symbol may retrieve word variants: (("improving basic performance metrics.") or ("improving basic performance evidence."))*.