Perhaps you should try some spelling variations:
"improving poor performance series." » "improving poor performance studies.", "improving poor performance size.", "improving sector performance series.", "improving power performance series.", "improving food performance series.", "improving peer performance series."
"improving ict performance measures." » "improving act performance measures.", "improving iot performance measures.", "improving lift performance measures.", "improving co performance measures.", "improving eco performance measures.", "improving its performance measures."

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving poor performance series.") OR ("improving ict performance measures."))~.
• Removing quotes may allow a broader search: (( improving poor performance series. ) or ( improving ict performance measures. ))~.
• Adding a wildcard symbol may retrieve word variants: (("improving poor performance series.") or ("improving ict performance measures."))*.