Perhaps you should try some spelling variations:
"improving railway performance metrics." » "improving utility performance metrics.", "improving railway performance contracts.", "improving railway performance measures.", "improving railway performance contract.", "improving rail performance metrics.", "improving early performance metrics."
"improving rural performance based." » "improving pupil performance based.", "improving thermal performance based.", "improving overall performance based.", "improving rural performance measures.", "improving urban performance based.", "improving social performance based."

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