Perhaps you should try some spelling variations:
"improving workers performance metrics." » "improving worker performance metrics.", "improving work performance metrics.", "improving markets performance metrics.", "improving workers performance measures.", "improving farmers performance metrics.", "employing workers performance metrics."
"improving urban performance contracts." » "improving bank performance contracts.", "improving loan performance contracts.", "improving human performance contracts."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving urban performance contracts.") or ("improving workers performance metrics."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving urban performance contracts.") OR ("improving workers performance metrics."))*.
• Removing quotes may allow a broader search: (( improving urban performance contracts. ) or ( improving workers performance metrics. ))*.