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 crop performance series." » "improving crop performance studies.", "improving crop performance size.", "improving group performance series.", "improving top performance series.", "improving do performance series.", "improving co performance series.", "improving pro performance series.", "improving macro 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 ("improving crop performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving can performance series.") OR ("improving crop performance series.")).
• Removing quotes may allow a broader search: (( improving can performance series. ) or ( improving crop performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving can performance series.") or ("improving crop performance series."))*.