Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
x hoi » xa hoi, o hoi, x ho

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) OR (hieu va)) am thuc ((va danh) or (va hanh)) mai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu van) OR (hieu va)) am thuc ((va danh) OR (va hanh)) mai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu van) OR (hieu va)) am thuc ((va danh) or (va hanh)) mai va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. ((hieu van) OR (hieu va)) am thuc ((va danh) or (va hanh)) mai va triet*.