Perhaps you should try some spelling variations:
"improving co performance contract." » "improving co performance contracts.", "improving do performance contract.", "improving crop performance contract.", "improving job performance contract.", "improving _ performance contract.", "improving macro performance contract.", "improving food performance contract."
"improving land performance series." » "improving land performance metrics.", "improving land performance reviews.", "improving land performance review.", "improving plant performance series.", "improving bank performance series.", "improving loan performance series.", "improved land performance series."

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

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