Perhaps you should try some spelling variations:
"improving job performance contract." » "improving job performance contracts.", "improving poor performance contract.", "improving loan performance contract.", "improving port performance contract.", "improving co performance contract.", "improving food performance contract.", "improving soil performance contract."
"improving road performance series." » "improving road performance metrics.", "improving road performance reviews.", "improving road performance review.", "improving board performance series.", "improving loan performance series.", "improving good performance series.", "improving food performance series.", "improving urban performance series.", "improving rural 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 road performance series.") or ("improving job performance contract."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving road performance series.") OR ("improving job performance contract.")).
• Removing quotes may allow a broader search: (( improving road performance series. ) or ( improving job performance contract. )).
• Adding a wildcard symbol may retrieve word variants: (("improving road performance series.") or ("improving job performance contract."))*.