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

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

• 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 hanh) OR (van 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 am thuc ((va danh) or (((va hanh) OR (van hanh)))) mai va triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van am thuc ((va danh) or (((va hanh) OR (van hanh)))) mai va triet*.