Perhaps you should try some spelling variations:
chief economists » chief economist, how economists, women economists
modern economic » models economic, modern economy, modeling economic
world's best » world's most, world's first
bank chief » beck chief, bank chinese
world beck » world back, world black, world book
world best » world test, world better

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 beck) OR (((world best) OR (world's best)))) modern economic ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( world bank chief economists ) or ( ((world beck) or (((world best) OR (world's best)))) modern economic ))*".