Perhaps you should try some spelling variations:
"improving maternal performance metrics." » "improving national performance metrics.", "improving thermal performance metrics.", "improving lanterns performance metrics.", "improving maternal performance contracts.", "improving maternal performance measures.", "improving maternal performance contract.", "improve maternal performance metrics.", "improving water performance metrics."
"improving social performance targets." » "improving school performance targets.", "improving fiscal performance targets.", "improving financial performance targets."

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

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