Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hieu van » thien van, lieu va, hieu ve
thai son » thai den, thai do, thai hoc
dua tren » dung tren
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
son va » song va, son la, lon va
vi dua » vi du, vi dum, vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky dang xay hoi. ((hieu van) or (hieu va)) thai son va hanh vi dua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky dang xay hoi. ((hieu van) OR (hieu va)) thai son va hanh vi dua tren.
• Adding a wildcard symbol may retrieve word variants: te sac ky dang xay hoi. ((hieu van) or (hieu va)) thai son va hanh vi dua tren*.