Perhaps you should try some spelling variations:
thien van » thi van
thanh tai » thanh hai, thanh toan, thanh san
hieu van » hieu va, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
lam duc » lam duoc, pham duc, nam duoc
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang x hoi. ((hieu van) or (thien van)) lam duc ban ((thanh tai) OR (doanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu van) OR (thien van)) lam duc ban ((thanh tai) OR (doanh tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu van) or (thien van)) lam duc ban ((thanh tai) OR (doanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. ((hieu van) or (thien van)) lam duc ban ((thanh tai) OR (doanh tai)) cua tre*.