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 plant performance evidence." » "improving port performance evidence.", "improving court performance evidence.", "improving land performance evidence.", "improving place performance evidence.", "improved plant performance evidence."

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