Perhaps you should try some spelling variations:
"improved land performance series." » "improved land performance studies.", "improved land performance size.", "improved plant performance series.", "improved fund performance series.", "improved und performance series.", "improve land performance series."
"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."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("improved land performance series.") or ("improving poor performance review."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improved land performance series.") OR ("improving poor performance review.")).
• Removing quotes may allow a broader search: (( improved land performance series. ) or ( improving poor performance review. )).
• Adding a wildcard symbol may retrieve word variants: (("improved land performance series.") or ("improving poor performance review."))*.