Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
tham duc » pham duc, tham du, than duc
te sach » toc sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
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: te sach ky nang cao hoi. ((hieu van) OR (lieu va)) tham duc ((va hanh) or (va danh)) lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang cao hoi. ((hieu van) OR (lieu va)) tham duc ((va hanh) OR (va danh)) lai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang cao hoi. ((hieu van) OR (lieu va)) tham duc ((va hanh) or (va danh)) lai cua tre*".