Perhaps you should try some spelling variations:
"improve contrast performance metrics." » "improve contract performance metrics.", "improve contractor performance metrics.", "improve control performance metrics.", "improve contrast performance measures.", "improve content performance metrics.", "image contrast performance metrics."
"improving poor performance review." » "improving poor performance risk.", "improving poor performance evidence.", "improving sector performance review.", "improving power performance review.", "improving food performance review.", "improving peer performance review."

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