Perhaps you should try some spelling variations:
land planning » based planning, road planning
dam planning » term planning, from planning, 2 planning
china tan » china top, china two, china taiwan
yong minh » gong min, jong min, sang minh
tan yong » tan hong, tan kong, tan yang
cong tan » hong tan, congo can, cong sun
cong van » congo can, 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: ((land planning) OR (dam planning)) can china tan yong minh ((cong tan) OR (cong van)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((land planning) OR (dam planning)) can china tan yong minh ((cong tan) or (cong van)) ;~".
• Adding a wildcard symbol may retrieve word variants: ((land planning) OR (dam planning)) can china tan yong minh ((cong tan) or (cong van)) ;*.