Perhaps you should try some spelling variations:
dang mat » dang vat, dang mau, dung mat
hieu va » lieu va, hieu qua
ky dang » ky nang, ky danh
mat hoi » mai hoi, sat hoi, mat troi
hieu ve » hieu van
cac tuc » cac toc, cac tu, cac tac
va dan » va dao, va dau, va dap
va cua » va chua, via cua, ca cua
ca dan » cac dan, ca dao
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky dang mat hoi. ((hieu ve) or (hieu va)) cac tuc ((va dan) OR (ca dan)) va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky dang mat hoi. ((hieu ve) OR (hieu va)) cac tuc ((va dan) OR (ca dan)) va cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky dang mat hoi. ((hieu ve) or (hieu va)) cac tuc ((va dan) OR (ca dan)) va cua te*".