Perhaps you should try some spelling variations:
"improving maternal performance contracts." » "improving materials performance contracts.", "improving external performance contracts.", "improving national performance contracts.", "improve maternal performance contracts.", "improving water performance contracts."
"improving country performance metrics." » "improving country performance measures.", "improving voluntary performance metrics.", "importing country performance metrics.", "improving community performance metrics."

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 country performance metrics.") OR ("improving maternal performance contracts."))~.
• Removing quotes may allow a broader search: (( improving country performance metrics. ) or ( improving maternal performance contracts. ))~.
• Adding a wildcard symbol may retrieve word variants: (("improving country performance metrics.") or ("improving maternal performance contracts."))*.