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 road performance contract."
"improving trade performance series." » "improving trade performance metrics.", "improving trade performance reviews.", "improving trade performance review.", "improving road performance series.", "improving tax performance series.", "improving teacher 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 trade performance series.") OR ("improving job performance contract."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"improving trade performance series.\") OR (\"improving job performance contract.\"))".
• Removing quotes may allow a broader search: (( improving trade performance series. ) OR ( improving job performance contract. )).
• Adding a wildcard symbol may retrieve word variants: (("improving trade performance series.") OR ("improving job performance contract."))*.