Perhaps you should try some spelling variations:
ban doanh » van doanh, san doanh, ban danh
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
x hoi » o hoi, x ho, 5 hoi

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 sach) OR (toc sach)) ky nang ((x hoi) OR (xa hoi)). hieu ve cac duc ban doanh tai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang ((x hoi) OR (xa hoi)). hieu ve cac duc ban doanh tai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang ((x hoi) OR (xa hoi)). hieu ve cac duc ban doanh tai cua tre*.