Perhaps you should try some spelling variations:
"improving do performance contract." » "improving do performance contracts.", "improving job performance contract.", "improving low performance contract.", "improving _ performance contract.", "improving co performance contract.", "improving food performance contract."
"improving local performance series." » "improving local performance metrics.", "improving local performance reviews.", "improving local performance review.", "improving social performance series.", "improving loan performance series.", "improving fiscal performance series.", "improving global performance series."

Try widening your search to All Fields.

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

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