Perhaps you should try some spelling variations:
"improving company performance contract." » "improving company performance contracts.", "improving country performance contract.", "improve company performance contract.", "improving compliance performance contract.", "improving community performance contract."
"improving thermal performance evidence." » "improving external performance evidence.", "improving animal performance evidence.", "improving erm 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 thermal performance evidence.") OR ("improving company performance contract."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving thermal performance evidence.\") OR (\"improving company performance contract.\"))".
• Removing quotes may allow a broader search: (( improving thermal performance evidence. ) OR ( improving company performance contract. )).
• Adding a wildcard symbol may retrieve word variants: (("improving thermal performance evidence.") OR ("improving company performance contract."))*.