Perhaps you should try some spelling variations:
"improving firm performance review." » "improving firm performance risk.", "improving firm performance evidence.", "improving firms performance review.", "improving air performance review.", "improving erm performance review."
"improving sharia performance based." » "improving sharia performances based.", "improving sharing performance based.", "improving chart performance based.", "improving shared performance based.", "improving spatial performance based.", "improving static performance based."

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

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