Perhaps you should try some spelling variations:
"improving maternal performance contracts." » "improving materials performance contracts.", "improving external performance contracts.", "improving national performance contracts.", "improve maternal performance contracts.", "improving water performance contracts."
"improving country performance contract." » "improving voluntary performance contract.", "importing country performance contract.", "improving community performance contract."

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 contract.") or ("improving maternal performance contracts."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving country performance contract.") OR ("improving maternal performance contracts.")).
• Removing quotes may allow a broader search: (( improving country performance contract. ) or ( improving maternal performance contracts. )).
• Adding a wildcard symbol may retrieve word variants: (("improving country performance contract.") or ("improving maternal performance contracts."))*.