Perhaps you should try some spelling variations:
"Improving contract performance evidence." » "Improving country performance evidence.", "Improving court performance evidence.", "Improving economic performance evidence."
improving contract » improve contract, improving central, improve contrast
"improving loan performance series." » "improving loan performance studies.", "improving loan performance size.", "improving local performance series.", "improving land performance series.", "improving lead performance series."

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 contract performance evidence.") OR ("improving loan performance series."))~.
• Removing quotes may allow a broader search: (( Improving contract performance evidence. ) or ( improving loan performance series. ))~.
• Adding a wildcard symbol may retrieve word variants: (("Improving contract performance evidence.") or ("improving loan performance series."))*.