Perhaps you should try some spelling variations:
"improving urban performance metrics." » "improving urban performance measures.", "improving bank performance metrics.", "improving loan performance metrics.", "improving human 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."

You may be able to get more results by adjusting your search query.

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