Perhaps you should try some spelling variations:
chuan quoc » cua quoc, phan quoc, chua nuoc
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hanh dai » hanh tai, hanh dao, vanh dai
hieu ve » hieu va
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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: toc sach y nang x hoi. ((hieu ve) OR (hieu van)) ((chuan quoc) OR (han quoc)) va hanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang x hoi. ((hieu ve) OR (hieu van)) ((chuan quoc) or (han quoc)) va hanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang x hoi. ((hieu ve) OR (hieu van)) ((chuan quoc) or (han quoc)) va hanh dai cua tre*.