Perhaps you should try some spelling variations:
"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."
"improving land performance contracts." » "improving plant performance contracts.", "improving fund performance contracts.", "improving und performance contracts."

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