Perhaps you should try some spelling variations:
"improving human performance metrics." » "improving human performance measures.", "improving thermal performance metrics.", "improving chain performance metrics."
"Improving loan performance series." » "Improving loan performance studies.", "Improving loan performance size."
improving loan » improving local, improving land, improving lead

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("Improving loan performance series.") OR ("improving human performance metrics."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"Improving loan performance series.\") OR (\"improving human performance metrics.\"))".
• Removing quotes may allow a broader search: (( Improving loan performance series. ) OR ( improving human performance metrics. )).
• Adding a wildcard symbol may retrieve word variants: (("Improving loan performance series.") OR ("improving human performance metrics."))*.