Perhaps you should try some spelling variations:
"improving crop performance reviews." » "improving crop performance review.", "improving crop performance reports.", "improving crop performance results.", "improving poor performance reviews.", "improving job performance reviews.", "improving city performance reviews.", "improving co performance reviews.", "improving macro performance reviews.", "improving food performance reviews."
"improving urban performance risks." » "improving bank performance risks.", "improving loan performance risks.", "improving can performance risks.", "improving urban performance risk.", "improving urban performance issues.", "improving urban performance based."

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

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