Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh do » thanh de, thanh pho, thanh hoa
dang xay » dang van, van xay
tu tang » tuc tang, tu trang, tu tong
duc van » duc va, duc tan, duc manh
ca viet » va viet, co viet, hoa viet
tang ky » dang ky, trong ky, tang khu
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
va cai » va dai, va cao
do ca » do cao, do cac, do cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu tang ky dang xay hoi. hieu ((((va cai) OR (va bai))) or (va cac)) duc van thanh do ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu tang ky dang xay hoi. hieu ((((va cai) OR (va bai))) OR (va cac)) duc van thanh do ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu tang ky dang xay hoi. hieu ((((va cai) OR (va bai))) or (va cac)) duc van thanh do ca viet".
• Adding a wildcard symbol may retrieve word variants: tu tang ky dang xay hoi. hieu ((((va cai) OR (va bai))) or (va cac)) duc van thanh do ca viet*.