Perhaps you should try some spelling variations:
"improving quality performance series." » "improving utility performance series.", "improving safety performance series.", "improving city performance series.", "improving quality performance metrics.", "improving quality performance reviews.", "improving quality performance review.", "improving health performance series."
"improving country performance evidence." » "improving voluntary performance evidence.", "importing country performance evidence.", "borrowing country performance evidence."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving quality performance series.") OR ("improving country performance evidence."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving quality performance series.\") OR (\"improving country performance evidence.\"))".
• Removing quotes may allow a broader search: (( improving quality performance series. ) OR ( improving country performance evidence. )).
• Adding a wildcard symbol may retrieve word variants: (("improving quality performance series.") OR ("improving country performance evidence."))*.