Perhaps you should try some spelling variations:
"improving emotional performance reports." » "improving national performance reports.", "improving operational performance reports.", "improving educational performance reports.", "improving maternal performance reports.", "improving emotional performance report."
"improve maternal performance series." » "improve materials performance series.", "improve external performance series.", "improve national performance series.", "improve maternal performance studies.", "improve maternal performance size.", "improving maternal performance series.", "improve water performance series."

Try widening your search to All Fields.

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

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