Perhaps you should try some spelling variations:
"improved land performance contract." » "improved land performance contracts.", "improved plant performance contract.", "improved fund performance contract.", "improved und performance contract."
"improving can performance series." » "improving can performance studies.", "improving can performance size.", "improving chain performance series.", "improving loan performance series.", "improving human performance series.", "improving care performance series.", "improving a performance series.", "improving co 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 can performance series.") or ("improved land performance contract."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving can performance series.") OR ("improved land performance contract.")).
• Removing quotes may allow a broader search: (( improving can performance series. ) or ( improved land performance contract. )).
• Adding a wildcard symbol may retrieve word variants: (("improving can performance series.") or ("improved land performance contract."))*.