Perhaps you should try some spelling variations:
"world bank chief economists" » "world bank chief economist", "world bank how economists", "world bank women economists", "world beck chief economists", "world bank chinese economists"
"world sick mena economies" » "world sick les economies", "world sick des economies", "world sick area economies", "world since mena economies", "world six mena economies", "world si mena economies", "world sick men economies", "world sick men's economies", "world sick man economies"
"world sick mena economic" » "world sick media economic", "world sick kenya economic", "world sick sea economic", "world since mena economic", "world six mena economic", "world si mena economic", "world sick men economic", "world sick men's economic", "world sick man economic"

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: (("world bank chief economists") OR ((("world sick mena economic") OR ("world sick mena economies")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"world bank chief economists\") or (((\"world sick mena economic\") OR (\"world sick mena economies\"))))".
• Removing quotes may allow a broader search: (( world bank chief economists ) or ((( world sick mena economic ) OR ( world sick mena economies )))).
• Adding a wildcard symbol may retrieve word variants: (("world bank chief economists") or ((("world sick mena economic") OR ("world sick mena economies"))))*.