Perhaps you should try some spelling variations:
doanh dai » doanh tai, doanh dao, doanh giai
hieu van » hieu va, thien van, lieu va
duong va » duong van, dung va, luong va
nang xa » nang x, lang xa, nang ma
van lam » van nam
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky

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: te sac ky nang xa hoi. hieu van lam ((duong va) OR (duc va)) doanh dai ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky nang xa hoi. hieu van lam ((duong va) or (duc va)) doanh dai ((cua tre) OR (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: te sac ky nang xa hoi. hieu van lam ((duong va) or (duc va)) doanh dai ((cua tre) OR (cuu tre))*.