Perhaps you should try some spelling variations:
dam planning » term planning, from planning, land planning
planning can » planning chain, planning case, planning land
china tan » china top, china two, china taiwan
sang minh » kang minah, anh minh, song min
congo can » congo call, congo a, congo war
tan sang » tan yang, tang tang, tan hong
cong van » duong van, cong sun

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: dam planning can china tan sang minh ((congo can) OR (cong van)) ;~.
• Adding a wildcard symbol may retrieve word variants: dam planning can china tan sang minh ((congo can) or (cong van)) ;*.