Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va danh » va dinh, dia danh, va thanh
va hanh » van hanh, va thanh, ban hanh
van am » van nam, van lam, van dam
va dan » ca dan, va dao, va dau
x hoi » xa hoi, o hoi, x ho
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang x hoi. hieu van am thuc ((((va danh) or (va dan))) or (va hanh)) mai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu van am thuc ((((va danh) OR (va dan))) OR (va hanh)) mai va thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van am thuc ((((va danh) or (va dan))) or (va hanh)) mai va thiet*.