Perhaps you should try some spelling variations:
"improving birth performance risk." » "improving high performance risk.", "improving growth performance risk.", "improving health performance risk.", "improving birth performance 2019.", "improving air performance risk."
"improving care performance evidence." » "improving trade performance evidence.", "improving drive performance evidence.", "improving 2 performance evidence.", "improving early performance evidence.", "improving air performance evidence.", "improving data 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 birth performance risk.") OR ("improving care performance evidence."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving birth performance risk.\") OR (\"improving care performance evidence.\"))".
• Removing quotes may allow a broader search: (( improving birth performance risk. ) OR ( improving care performance evidence. )).
• Adding a wildcard symbol may retrieve word variants: (("improving birth performance risk.") OR ("improving care performance evidence."))*.