Perhaps you should try some spelling variations:
"improving power performance studies." » "improving power performance audits.", "improving power performance audit.", "improving power performance standards.", "improving poor performance studies.", "improving worker performance studies.", "improving core performance studies.", "improving peer performance studies.", "improving sewer performance studies."
"improving country performance review." » "improving country performance risk.", "improving country performance evidence.", "improving voluntary performance review.", "importing country performance review.", "improving community performance review."

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

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