Perhaps you should try some spelling variations:
"improving thermal performance series." » "improving thermal performance studies.", "improving thermal performance size.", "improving external performance series.", "improving animal performance series.", "improving erm performance series."
"improving larval performance risk." » "improving level performance risk.", "improving maximal performance risk.", "improving fiscal performance risk.", "improving local performance risk.", "improving legal performance risk.", "improving land performance risk.", "improving larval performance 2019."

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

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