Perhaps you should try some spelling variations:
world powers » world power, world papers, world pioneers
powers asia » power asia, powers persia, powers david
black david » clark david
jack david » back david, gacek david, jacob david
how world » how would, new world, how work

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: 2008 how world powers asia ((jack david) OR (black david))*.