Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van than » van thanh, van thang, van tuan
than duc » tran duc, phan duc, than doc
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cao hoi » cau hoi, co hoi, cao hoc
va danh » va dinh, va dan, va hanh
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty nang cao hoi. hieu van than duc ((ban thanh) or (va danh)) lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang cao hoi. hieu van than duc ((ban thanh) OR (va danh)) lai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang cao hoi. hieu van than duc ((ban thanh) or (va danh)) lai cua tre*.