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
te sach » toc sach
nang xa » nang x, lang xa, nang ma
van lam » van nam
cua tre » cua te, cuu tre, cua triet
te sac » te cac, te san

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) OR (te sach)) ky nang xa hoi. hieu van lam ((duong va) or (duc va)) doanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sac) OR (te sach)) ky nang xa hoi. hieu van lam ((duong va) OR (duc va)) doanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sac) OR (te sach)) ky nang xa hoi. hieu van lam ((duong va) or (duc va)) doanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sac) OR (te sach)) ky nang xa hoi. hieu van lam ((duong va) or (duc va)) doanh dai cua tre*.