Perhaps you should try some spelling variations:
thien van » thi van
ban doanh » van doanh, san doanh, ban danh
hieu van » hieu va, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
lam duc » lam duoc, pham duc, nam duoc
duc ban » duc tan, duc van, dua ban
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 y nang o hoi. ((hieu van) or (thien van)) lam duc ban doanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang o hoi. ((hieu van) OR (thien van)) lam duc ban doanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hoi. ((hieu van) or (thien van)) lam duc ban doanh tai cua tre*.