Perhaps you should try some spelling variations:
ban thanh » ban hang
ban hanh » ban hang
te sach » toc sach
cac dac » cac dan, cac dai, cac bac
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
cac duc » cac du, cao duc, cac nuoc
hieu ve » hieu va, hieu van
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: te sach y nang o hoi. hieu ve ((cac duc) or (cac dac)) ((ban thanh) OR (ban hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang o hoi. hieu ve ((cac duc) OR (cac dac)) ((ban thanh) OR (ban hanh)) vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang o hoi. hieu ve ((cac duc) or (cac dac)) ((ban thanh) OR (ban hanh)) vai cua tre*".