Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
toi tap » toi gap, toan tap, tong tap
cua tre » cua te, cuu tre, cua triet
vu san » va san, vu ban
tu ban » thu ban, te ban
toi ta » toi la, toi da, toi te

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: ((vu san) OR (tu ban)) ky nang cao hoi. hieu va cac ((toi ta) OR (toi tap)) hanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu san) or (tu ban)) ky nang cao hoi. hieu va cac ((toi ta) OR (toi tap)) hanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((vu san) or (tu ban)) ky nang cao hoi. hieu va cac ((toi ta) OR (toi tap)) hanh dai cua tre*.