Perhaps you should try some spelling variations:
"improving seismic performance series." » "improving economic performance series.", "improving academic performance series.", "improving seismic performance studies.", "improving seismic performance size.", "improving semantic performance series.", "improving service performance series.", "improving basic performance series."
"improving board performance risk." » "improving court performance risk.", "improving good performance risk.", "improving based performance risk.", "improving board performance 2019.", "improving food performance risk.", "improving care performance risk.", "improving blood performance risk."

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

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