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 school performance targets." » "improving schools performance targets.", "improving preschool performance targets.", "improve school performance targets."

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