Perhaps you should try some spelling variations:
"improving export performance series." » "improving export performance studies.", "improving export performance size.", "improving exposure performance series.", "improving eap performance series.", "improving eco performance series."
"improving job performance contracts." » "improving court performance contracts.", "improving co performance contracts.", "improving food performance contracts.", "improving crop 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 export performance series.") or ("improving job performance contracts."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving export performance series.") OR ("improving job performance contracts.")).
• Removing quotes may allow a broader search: (( improving export performance series. ) or ( improving job performance contracts. )).
• Adding a wildcard symbol may retrieve word variants: (("improving export performance series.") or ("improving job performance contracts."))*.