Perhaps you should try some spelling variations:
"improving human performance contract." » "improving human performance contracts.", "improving loan performance contract.", "improving thermal performance contract.", "improving chain performance contract."
"improving access performance metrics." » "improving access performance measures.", "improving excess performance metrics.", "improving process performance metrics.", "improving painless performance metrics."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("improving human performance contract.") or ("improving access performance metrics."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving human performance contract.") OR ("improving access performance metrics."))*.
• Removing quotes may allow a broader search: (( improving human performance contract. ) or ( improving access performance metrics. ))*.