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

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 contracts.") OR ("improve maternal performance contract."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving country performance contracts.\") OR (\"improve maternal performance contract.\"))".
• Removing quotes may allow a broader search: (( improving country performance contracts. ) OR ( improve maternal performance contract. )).
• Adding a wildcard symbol may retrieve word variants: (("improving country performance contracts.") OR ("improve maternal performance contract."))*.