Perhaps you should try some spelling variations:
"improving firms performance contract." » "improving firms performance contracts.", "improving firm performance contract.", "improving firm performances contract.", "improving funds performance contract.", "improving farmers performance contract.", "importing firms performance contract.", "improving air performance contract."
"improving loan performance evidence." » "improving local performance evidence.", "improving land performance evidence.", "improving lead performance evidence."

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