Perhaps you should try some spelling variations:
"improving baseline performance series." » "improving baldrige performance series.", "improving based performance series.", "improving basic performance series.", "improving modeling performance series.", "improving vaccine performance series.", "improving baseline performance studies.", "improving baseline performance size."
"improving air performance series." » "improving air performance studies.", "improving air performance size.", "improving zur performance series.", "improving bar performance series.", "improving der performance series.", "improving _ 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 baseline performance series.") or ("improving air performance series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving baseline performance series.") OR ("improving air performance series.")).
• Removing quotes may allow a broader search: (( improving baseline performance series. ) or ( improving air performance series. )).
• Adding a wildcard symbol may retrieve word variants: (("improving baseline performance series.") or ("improving air performance series."))*.