Perhaps you should try some spelling variations:
investment treaties » investment strategies, investment activities, investment incentives
investment does » investment data, investment assets, investment across
kent foreign » net foreign, debt foreign, den foreign
kent trade » net trade, best trade, nest trade
west trade » best trade, nest trade, wheat trade

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: (( h. kent foreign investment treaties ) OR ( h. ((kent trade) OR (west trade)) investment does ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( h. kent foreign investment treaties ) or ( h. ((kent trade) OR (west trade)) investment does ))~".
• Adding a wildcard symbol may retrieve word variants: (( h. kent foreign investment treaties ) or ( h. ((kent trade) OR (west trade)) investment does ))*.