Perhaps you should try some spelling variations:
"improve maternal performance contract." » "improve national performance contract.", "improve thermal performance contract.", "improve lanterns performance contract.", "improve maternal performance contracts.", "improving maternal performance contract.", "improve water performance contract."
"improving country performance metrics." » "improving country performance contracts.", "improving country performance measures.", "improving voluntary performance metrics.", "importing country performance metrics.", "borrowing country performance metrics."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving country performance metrics.") or ("improve maternal performance contract."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving country performance metrics.") OR ("improve maternal performance contract.")).
• Removing quotes may allow a broader search: (( improving country performance metrics. ) or ( improve maternal performance contract. )).
• Adding a wildcard symbol may retrieve word variants: (("improving country performance metrics.") or ("improve maternal performance contract."))*.